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Vulnerability details: VCID-4ggm-x6t1-juhb
Vulnerability ID VCID-4ggm-x6t1-juhb
Aliases CVE-2021-40839
GHSA-gh8j-2pgf-x458
PYSEC-2021-345
Summary denial of service
Status Published
Exploitability 0.5
Weighted Severity 8.0
Risk 4.0
Affected and Fixed Packages Package Details
Weaknesses (3)
CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
System Score Found at
epss 0.17289 https://api.first.org/data/v1/epss?cve=CVE-2021-40839
epss 0.17289 https://api.first.org/data/v1/epss?cve=CVE-2021-40839
epss 0.17289 https://api.first.org/data/v1/epss?cve=CVE-2021-40839
epss 0.17289 https://api.first.org/data/v1/epss?cve=CVE-2021-40839
cvssv3.1 7.5 https://github.com/advisories/GHSA-gh8j-2pgf-x458
cvssv3.1_qr HIGH https://github.com/advisories/GHSA-gh8j-2pgf-x458
cvssv4 8.7 https://github.com/advisories/GHSA-gh8j-2pgf-x458
generic_textual HIGH https://github.com/advisories/GHSA-gh8j-2pgf-x458
cvssv3.1 7.5 https://github.com/aresch/rencode
cvssv4 8.7 https://github.com/aresch/rencode
generic_textual HIGH https://github.com/aresch/rencode
cvssv3.1 7.5 https://github.com/aresch/rencode/commit/572ff74586d9b1daab904c6f7f7009ce0143bb75
cvssv4 8.7 https://github.com/aresch/rencode/commit/572ff74586d9b1daab904c6f7f7009ce0143bb75
generic_textual HIGH https://github.com/aresch/rencode/commit/572ff74586d9b1daab904c6f7f7009ce0143bb75
cvssv3.1 7.5 https://github.com/aresch/rencode/pull/29
cvssv4 8.7 https://github.com/aresch/rencode/pull/29
generic_textual HIGH https://github.com/aresch/rencode/pull/29
cvssv3.1 7.5 https://github.com/pypa/advisory-database/tree/main/vulns/rencode/PYSEC-2021-345.yaml
cvssv4 8.7 https://github.com/pypa/advisory-database/tree/main/vulns/rencode/PYSEC-2021-345.yaml
generic_textual HIGH https://github.com/pypa/advisory-database/tree/main/vulns/rencode/PYSEC-2021-345.yaml
cvssv3.1 7.5 https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BMVQRPDVSVZNGGX57CFKCYT3DEYO4QB6
cvssv4 8.7 https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BMVQRPDVSVZNGGX57CFKCYT3DEYO4QB6
generic_textual HIGH https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BMVQRPDVSVZNGGX57CFKCYT3DEYO4QB6
cvssv3.1 7.5 https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MCLETLGVM5DBX6QNHQFW6TWGO5T3DENY
cvssv4 8.7 https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MCLETLGVM5DBX6QNHQFW6TWGO5T3DENY
generic_textual HIGH https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MCLETLGVM5DBX6QNHQFW6TWGO5T3DENY
cvssv3.1 7.5 https://nvd.nist.gov/vuln/detail/CVE-2021-40839
cvssv4 8.7 https://nvd.nist.gov/vuln/detail/CVE-2021-40839
generic_textual HIGH https://nvd.nist.gov/vuln/detail/CVE-2021-40839
cvssv3.1 7.5 https://pypi.org/project/rencode/#history
cvssv4 8.7 https://pypi.org/project/rencode/#history
generic_textual HIGH https://pypi.org/project/rencode/#history
cvssv3.1 7.5 https://seclists.org/fulldisclosure/2021/Sep/16
cvssv4 8.7 https://seclists.org/fulldisclosure/2021/Sep/16
generic_textual HIGH https://seclists.org/fulldisclosure/2021/Sep/16
archlinux Low https://security.archlinux.org/AVG-2372
cvssv3.1 7.5 https://security.netapp.com/advisory/ntap-20211008-0001
cvssv4 8.7 https://security.netapp.com/advisory/ntap-20211008-0001
generic_textual HIGH https://security.netapp.com/advisory/ntap-20211008-0001
Reference id Reference type URL
https://api.first.org/data/v1/epss?cve=CVE-2021-40839
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-40839
https://github.com/advisories/GHSA-gh8j-2pgf-x458
https://github.com/aresch/rencode
https://github.com/aresch/rencode/commit/572ff74586d9b1daab904c6f7f7009ce0143bb75
https://github.com/aresch/rencode/pull/29
https://github.com/pypa/advisory-database/tree/main/vulns/rencode/PYSEC-2021-345.yaml
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BMVQRPDVSVZNGGX57CFKCYT3DEYO4QB6
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MCLETLGVM5DBX6QNHQFW6TWGO5T3DENY
https://nvd.nist.gov/vuln/detail/CVE-2021-40839
https://pypi.org/project/rencode/#history
https://seclists.org/fulldisclosure/2021/Sep/16
https://security.netapp.com/advisory/ntap-20211008-0001
AVG-2372 https://security.archlinux.org/AVG-2372
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/advisories/GHSA-gh8j-2pgf-x458
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

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high

low

none
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N Found at https://github.com/advisories/GHSA-gh8j-2pgf-x458
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

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none

passive

active

high

low

none

high

low

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low

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high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/aresch/rencode
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N Found at https://github.com/aresch/rencode
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

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passive

active

high

low

none

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none

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low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/aresch/rencode/commit/572ff74586d9b1daab904c6f7f7009ce0143bb75
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N Found at https://github.com/aresch/rencode/commit/572ff74586d9b1daab904c6f7f7009ce0143bb75
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

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none

passive

active

high

low

none

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none

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none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/aresch/rencode/pull/29
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N Found at https://github.com/aresch/rencode/pull/29
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

high

none

passive

active

high

low

none

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Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/pypa/advisory-database/tree/main/vulns/rencode/PYSEC-2021-345.yaml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N Found at https://github.com/pypa/advisory-database/tree/main/vulns/rencode/PYSEC-2021-345.yaml
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

high

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passive

active

high

low

none

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Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BMVQRPDVSVZNGGX57CFKCYT3DEYO4QB6
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N Found at https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BMVQRPDVSVZNGGX57CFKCYT3DEYO4QB6
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

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passive

active

high

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none

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Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MCLETLGVM5DBX6QNHQFW6TWGO5T3DENY
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N Found at https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MCLETLGVM5DBX6QNHQFW6TWGO5T3DENY
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

high

none

passive

active

high

low

none

high

low

none

high

low

none

high

low

none

high

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low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2021-40839
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N Found at https://nvd.nist.gov/vuln/detail/CVE-2021-40839
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

high

none

passive

active

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://pypi.org/project/rencode/#history
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N Found at https://pypi.org/project/rencode/#history
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

high

none

passive

active

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://seclists.org/fulldisclosure/2021/Sep/16
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N Found at https://seclists.org/fulldisclosure/2021/Sep/16
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

high

none

passive

active

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://security.netapp.com/advisory/ntap-20211008-0001
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N Found at https://security.netapp.com/advisory/ntap-20211008-0001
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

high

none

passive

active

high

low

none

high

low

none

high

low

none

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low

none

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low

none
Exploit Prediction Scoring System (EPSS)
Percentile 0.95186
EPSS Score 0.17289
Published At June 11, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-06-11T19:56:00.146170+00:00 Arch Linux Importer Import https://security.archlinux.org/AVG-2372 38.6.0