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Vulnerability details: VCID-dchf-rhvg-zycw
Vulnerability ID VCID-dchf-rhvg-zycw
Aliases CVE-2026-34835
GHSA-g2pf-xv49-m2h5
Summary rack: Rack: Host header poisoning due to malformed Host header bypasses validation
Status Published
Exploitability None
Weighted Severity None
Risk None
Affected and Fixed Packages Package Details
Weaknesses (3)
CWE-1286 Improper Validation of Syntactic Correctness of Input
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
cvssv3 4.8 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-34835.json
epss 0.00152 https://api.first.org/data/v1/epss?cve=CVE-2026-34835
cvssv3.1 4.8 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
cvssv3.1 4.8 https://github.com/rack/rack
generic_textual MODERATE https://github.com/rack/rack
cvssv3 4.8 https://github.com/rack/rack/security/advisories/GHSA-g2pf-xv49-m2h5
cvssv3.1 4.8 https://github.com/rack/rack/security/advisories/GHSA-g2pf-xv49-m2h5
generic_textual MODERATE https://github.com/rack/rack/security/advisories/GHSA-g2pf-xv49-m2h5
ssvc Track https://github.com/rack/rack/security/advisories/GHSA-g2pf-xv49-m2h5
cvssv3.1 4.8 https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rack/CVE-2026-34835.yml
generic_textual MODERATE https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rack/CVE-2026-34835.yml
cvssv3.1 4.8 https://nvd.nist.gov/vuln/detail/CVE-2026-34835
generic_textual MODERATE https://nvd.nist.gov/vuln/detail/CVE-2026-34835
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-34835.json
https://api.first.org/data/v1/epss?cve=CVE-2026-34835
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-34835
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
https://github.com/rack/rack
https://github.com/rack/rack/security/advisories/GHSA-g2pf-xv49-m2h5
https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rack/CVE-2026-34835.yml
https://nvd.nist.gov/vuln/detail/CVE-2026-34835
2454482 https://bugzilla.redhat.com/show_bug.cgi?id=2454482
GHSA-g2pf-xv49-m2h5 https://github.com/advisories/GHSA-g2pf-xv49-m2h5
USN-8182-1 https://usn.ubuntu.com/8182-1/
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-34835.json
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:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N Found at https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.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:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N Found at https://github.com/rack/rack
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:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N Found at https://github.com/rack/rack/security/advisories/GHSA-g2pf-xv49-m2h5
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: SSVCv2/E:N/A:N/T:P/P:M/B:A/M:M/D:T/2026-04-02T17:43:54Z/ Found at https://github.com/rack/rack/security/advisories/GHSA-g2pf-xv49-m2h5
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N Found at https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rack/CVE-2026-34835.yml
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:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2026-34835
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 0.35557
EPSS Score 0.00152
Published At May 29, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-05-29T08:41:27.767026+00:00 RedHat Importer Import https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-34835.json 38.6.0