Cross-Site Scripting (XSS) in gitlab (CVE-2026-8589)
Summary
Cross-site scripting in gitlab (CVE-2026-8589). Confidential information can be exposed externally. Mitigation: upgrade to 18.10.8, 18.11.5, 19.0.2 or later.
Original description
The description as published by the source.
GitLab has remediated an issue in GitLab EE affecting all versions from 13.1.4 before 18.10.8, 18.11 before 18.11.5, and 19.0 before 19.0.2 that under certain conditions could have allowed an authenticated user to add unauthorized email addresses to a targeted user's account due to improper sanitization of user-supplied input in certain group setting fields.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-8589 has been found in gitlab.
Confidential information can be exposed externally. CVSS score: 7.3/10.
What to do: upgrade gitlab to 18.10.8, 18.11.5, 19.0.2 or later.
If unsure, ask your IT team or search "gitlab CVE-2026-8589" on the vendor's site.
CVE-2026-8589 (gitlab) — CWE-79 / CVSS v3 7.3
Attack vector: remote (network-reachable)
Patched: 18.10.8, 18.11.5, 19.0.2 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Cross-site scripting (XSS) (CWE-79) exists in gitlab.
Check the vendor advisory for the affected versions of gitlab.
Severity: High (CVSS 7.3/10). Confidential information can be exposed externally.
Update to 18.10.8, 18.11.5, 19.0.2.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'gitlab' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'gitlab' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
gitlabを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade gitlab to 18.10.8, 18.11.5, 19.0.2ステージング環境で 18.10.8, 18.11.5, 19.0.2 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Ubuntu UBUNTU-CVE-2026-8589 gitlab
References
- advisory nvd.nist.gov
- advisory github.com
- package git://git@gitlab.com:gitlab-org/gitlab.git
- report hackerone.com
- web about.gitlab.com
- web gitlab.com
- web github.com
- web about.gitlab.com