CVE-2026-112212

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') in GitLab

GitLab GitLabApplications & CMS

CVSS

7.5High

ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV

Exploit odds (EPSS)0.19%Chance of exploitation activity in the next 30 days, higher than 8% of CVEs. Scored 23 Oct 2026FIRST EPSS

Fixed in19.3.6Also 19.4.3, 19.5.1CVE List

Published21 Oct 2026Updated 21 Oct 2026CVE List

What fixes it

19.3.6GitLabCVE List
19.4.3GitLabCVE List
19.5.1GitLabCVE List

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Reports 1

1 outlet mention it. Reports are not confirmation; each links to its source.

GitLab Critical Patch Release: 19.5.1, 19.4.3, 19.3.6, 19.2.9, 19.1.9, 19.0.10, 18.11.13GitLab releases, 21 Oct 2026

Description

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.3 before 19.3.6, 19.4 before 19.4.3, and 19.5 before 19.5.1 that, under certain conditions, an unauthenticated user could have poisoned a shared cache's OAuth/OIDC discovery document to redirect certain flows to an externally controlled server, due to improper trust of user-supplied values when constructing endpoint URLs in cached discovery responses.

Text from CVE List

Affected versions 3

GitLabaffected: 18.3 before 19.3.6CVE List
GitLabaffected: 19.4 before 19.4.3CVE List
GitLabaffected: 19.5 before 19.5.1CVE List