Vulnerability in twig/twig (CVE-2026-46634)
Summary
Vulnerability in twig/twig (CVE-2026-46634). Successful exploitation can lead to full system takeover. Exploitable via SourcePolicyInterface. Mitigation: upgrade to 3.26.0 or later.
Original description
The description as published by the source.
Twig is a template language for PHP. From 3.9.0 until 3.26.0, template_from_string() compiles an inner template under a synthesized string_template name that can fall outside a SourcePolicyInterface sandbox decision, allowing a sandboxed template that can call template_from_string and include to render an inner template without security policy enforcement. This issue is fixed in version 3.26.0.
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-2026-46634 has been found in twig/twig.
Attackers can target a specific entry point like SourcePolicyInterface over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 9.8/10.
What to do: upgrade twig/twig to 3.26.0 or later.
If unsure, ask your IT team or search "twig/twig CVE-2026-46634" on the vendor's site.
CVE-2026-46634 (twig/twig) — CWE-693 / CVSS v3 9.8
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: SourcePolicyInterface / template_from_string / include / SourcePolicy
Patched: 3.26.0 — 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.
A vulnerability (CWE-693) exists in twig/twig. Attackers reach the vulnerable code path via SourcePolicyInterface without authentication.
Check the vendor advisory for the affected versions of twig/twig. Attack surface: SourcePolicyInterface / template_from_string / include / SourcePolicy.
Severity: Critical (CVSS 9.8/10). Successful exploitation can lead to full system takeover.
Update to 3.26.0.
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 'twig/twig' . 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 'twig/twig' . | 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
twig/twig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 twig/twig to 3.26.0ステージング環境で 3.26.0 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
- Debian DEBIAN-CVE-2026-46634 php-twig Fixed in: 3.27.0-0+deb13u1
- Ubuntu UBUNTU-CVE-2026-46634 php-twig
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- patch github.com
- web github.com
- web symfony.com
- web github.com
- web github.com