Vulnerability in Mojolicious (CVE-2026-15747)
Summary
Vulnerability in Mojolicious (CVE-2026-15747). Confidential information can be exposed externally. Exploitable via csrf_token.
Original description
The description as published by the source.
Mojolicious versions from 4.59 before 9.48 for Perl expose a stable representation of the session CSRF token to a BREACH compression oracle.
_csrf_token generates and caches one token per session and returns the same value on every call, and _csrf_field places that value in a hidden csrf_token input. When a response carrying the token also echoes attacker-controlled input and is gzip-compressed, the chosen values and the resulting compressed lengths form a BREACH oracle.
An attacker able to query it can recover the token and pass csrf_protect validation.
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-2026-15747 has been found in Mojolicious.
Attackers can target a specific entry point like csrf_token over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 9.1/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Mojolicious CVE-2026-15747" on the vendor's site.
CVE-2026-15747 (Mojolicious) — CWE-204 / CVSS v3 9.1
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: csrf_token
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.
A vulnerability (CWE-204) exists in Mojolicious. Attackers reach the vulnerable code path via csrf_token without authentication.
Check the vendor advisory for the affected versions of Mojolicious. Attack surface: csrf_token.
Severity: Critical (CVSS 9.1/10). Confidential information can be exposed externally.
Update to the patched release per vendor advisory.
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 'Mojolicious' . 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 'Mojolicious' . | 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
Mojoliciousを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-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。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-15747 libmojolicious-perl
- Ubuntu UBUNTU-CVE-2026-15747 libmojolicious-perl
References
- web nvd.nist.gov
- web github.com
- web metacpan.org
- web github.com
- web openwall.com