CVE-2026-12635 | Reliance on Reverse DNS Resolution for a Security-Critical Action in GitLab

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 8.3 before 18.11.6, 19.0 before 19.0.3, and 19.1 before 19.1.1 that under certain conditions could have allowed an authenticated user with maintainer-role permissions to make requests to internal network resources through mirror synchronization due to improper URL validation.

Published: 2026-06-25 Last update: 2026-06-26 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-12635 is rated Low Risk (6.8/100): low exploitation likelihood (EPSS 0.17%). Mandatory action: Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-12635

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-25 0.17%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-12635

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
0.0 3.1 NONE
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
1.6 0.0 [email protected]
3.1 3.1 LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
1.6 1.4 [email protected]

Weakness enumeration for CVE-2026-12635

GitHub Security Advisory for CVE-2026-12635

GHSA-px7v-hx94-8wmf · Severity: low — GitLab has remediated an issue in GitLab CE/EE affecting all versions from 8.3 before 18.11.6, 19...

Affected software / configurations for CVE-2026-12635

Vendor Product Version Raw CPE
gitlab gitlab >= 8.3.0, < 18.11.6 cpe:2.3:a:gitlab:gitlab:*:*:*:*:*:*:*:*
gitlab gitlab >= 19.0.0, < 19.0.3 cpe:2.3:a:gitlab:gitlab:*:*:*:*:*:*:*:*
gitlab gitlab 19.1.0 cpe:2.3:a:gitlab:gitlab:19.1.0:*:*:*:*:*:*:*

References for CVE-2026-12635

cvelogic Threat Intelligence