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Vulnerability details: VCID-pu7p-7bnc-3ubx
Vulnerability ID VCID-pu7p-7bnc-3ubx
Aliases CVE-2021-26906
Summary An issue was discovered in res_pjsip_session.c in Digium Asterisk through 13.38.1; 14.x, 15.x, and 16.x through 16.16.0; 17.x through 17.9.1; and 18.x through 18.2.0, and Certified Asterisk through 16.8-cert5. An SDP negotiation vulnerability in PJSIP allows a remote server to potentially crash Asterisk by sending specific SIP responses that cause an SDP negotiation failure.
Status Published
Exploitability 0.5
Weighted Severity 5.3
Risk 2.6
Affected and Fixed Packages Package Details
Weaknesses (1)
CWE-404 Improper Resource Shutdown or Release
System Score Found at
epss 0.00506 https://api.first.org/data/v1/epss?cve=CVE-2021-26906
epss 0.00506 https://api.first.org/data/v1/epss?cve=CVE-2021-26906
epss 0.00506 https://api.first.org/data/v1/epss?cve=CVE-2021-26906
epss 0.00506 https://api.first.org/data/v1/epss?cve=CVE-2021-26906
epss 0.00506 https://api.first.org/data/v1/epss?cve=CVE-2021-26906
epss 0.00506 https://api.first.org/data/v1/epss?cve=CVE-2021-26906
epss 0.00506 https://api.first.org/data/v1/epss?cve=CVE-2021-26906
epss 0.00506 https://api.first.org/data/v1/epss?cve=CVE-2021-26906
epss 0.00506 https://api.first.org/data/v1/epss?cve=CVE-2021-26906
epss 0.00506 https://api.first.org/data/v1/epss?cve=CVE-2021-26906
epss 0.00506 https://api.first.org/data/v1/epss?cve=CVE-2021-26906
epss 0.00506 https://api.first.org/data/v1/epss?cve=CVE-2021-26906
epss 0.00506 https://api.first.org/data/v1/epss?cve=CVE-2021-26906
epss 0.00506 https://api.first.org/data/v1/epss?cve=CVE-2021-26906
epss 0.00506 https://api.first.org/data/v1/epss?cve=CVE-2021-26906
epss 0.00506 https://api.first.org/data/v1/epss?cve=CVE-2021-26906
cvssv2 4.3 https://nvd.nist.gov/vuln/detail/CVE-2021-26906
cvssv3.1 5.9 https://nvd.nist.gov/vuln/detail/CVE-2021-26906
Reference id Reference type URL
http://packetstormsecurity.com/files/161477/Asterisk-Project-Security-Advisory-AST-2021-005.html
https://api.first.org/data/v1/epss?cve=CVE-2021-26906
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-26906
https://downloads.asterisk.org/pub/security/
https://downloads.asterisk.org/pub/security/AST-2021-005.html
http://seclists.org/fulldisclosure/2021/Feb/61
https://issues.asterisk.org/jira/browse/ASTERISK-29196
983159 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=983159
cpe:2.3:a:digium:asterisk:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:digium:asterisk:*:*:*:*:*:*:*:*
cpe:2.3:a:digium:certified_asterisk:16.8:-:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:digium:certified_asterisk:16.8:-:*:*:*:*:*:*
cpe:2.3:a:digium:certified_asterisk:16.8:cert1-rc1:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:digium:certified_asterisk:16.8:cert1-rc1:*:*:*:*:*:*
cpe:2.3:a:digium:certified_asterisk:16.8:cert1-rc2:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:digium:certified_asterisk:16.8:cert1-rc2:*:*:*:*:*:*
cpe:2.3:a:digium:certified_asterisk:16.8:cert1-rc3:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:digium:certified_asterisk:16.8:cert1-rc3:*:*:*:*:*:*
cpe:2.3:a:digium:certified_asterisk:16.8:cert1-rc4:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:digium:certified_asterisk:16.8:cert1-rc4:*:*:*:*:*:*
cpe:2.3:a:digium:certified_asterisk:16.8:cert2:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:digium:certified_asterisk:16.8:cert2:*:*:*:*:*:*
cpe:2.3:a:digium:certified_asterisk:16.8:cert3:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:digium:certified_asterisk:16.8:cert3:*:*:*:*:*:*
cpe:2.3:a:digium:certified_asterisk:16.8:cert4:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:digium:certified_asterisk:16.8:cert4:*:*:*:*:*:*
cpe:2.3:a:digium:certified_asterisk:16.8:cert4-rc1:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:digium:certified_asterisk:16.8:cert4-rc1:*:*:*:*:*:*
cpe:2.3:a:digium:certified_asterisk:16.8:cert4-rc2:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:digium:certified_asterisk:16.8:cert4-rc2:*:*:*:*:*:*
cpe:2.3:a:digium:certified_asterisk:16.8:cert4-rc3:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:digium:certified_asterisk:16.8:cert4-rc3:*:*:*:*:*:*
cpe:2.3:a:digium:certified_asterisk:16.8:cert4-rc4:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:digium:certified_asterisk:16.8:cert4-rc4:*:*:*:*:*:*
cpe:2.3:a:digium:certified_asterisk:16.8:cert5:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:digium:certified_asterisk:16.8:cert5:*:*:*:*:*:*
CVE-2021-26906 https://nvd.nist.gov/vuln/detail/CVE-2021-26906
No exploits are available.
Vector: AV:N/AC:M/Au:N/C:N/I:N/A:P Found at https://nvd.nist.gov/vuln/detail/CVE-2021-26906
Exploitability (E) Access Vector (AV) Access Complexity (AC) Authentication (Au) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

high

functional

unproven

proof_of_concept

not_defined

local

adjacent_network

network

high

medium

low

multiple

single

none

none

partial

complete

none

partial

complete

none

partial

complete
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2021-26906
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
Exploit Prediction Scoring System (EPSS)
Percentile 0.65232
EPSS Score 0.00506
Published At July 30, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2025-07-31T08:36:30.498020+00:00 Alpine Linux Importer Import https://secdb.alpinelinux.org/edge/main.json 37.0.0