Cross-Site Scripting (XSS) in symfony/symfony (CVE-2026-45072)
Summary
Cross-site scripting in symfony/symfony (CVE-2026-45072). Risk of unauthorized operations or information disclosure. Exploitable via file_excerpt. Mitigation: upgrade to 8.0.12 or later.
Original description
The description as published by the source.
Symfony is a PHP framework for web and console applications and a set of reusable PHP components. From 6.4.24 until 6.4.40, 7.4.12, and 8.0.12, the development profiler file_excerpt Twig filter escapes PHP files through highlight_string() but interpolates lines from non-PHP files directly into elements, allowing stored XSS against a developer who opens an attacker-written file such as var/log/dev.log in the profiler. This issue is fixed in versions 6.4.40, 7.4.12, and 8.0.12.
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-2026-45072 has been found in symfony/symfony.
Attackers can target a specific entry point like file_excerpt over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.4/10.
What to do: upgrade symfony/symfony to 8.0.12 or later.
If unsure, ask your IT team or search "symfony/symfony CVE-2026-45072" on the vendor's site.
CVE-2026-45072 (symfony/symfony) — CWE-79 / CVSS v3 5.4
Attack vector: remote (network-reachable)
Attack surface: file_excerpt
Patched: 8.0.12 — 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 symfony/symfony. Attackers reach the vulnerable code path via file_excerpt.
Check the vendor advisory for the affected versions of symfony/symfony. Attack surface: file_excerpt.
Severity: Medium (CVSS 5.4/10). Risk of unauthorized operations or information disclosure.
Update to 8.0.12.
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 'symfony/symfony' . 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
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1Identify exposure identify
grep -r 'symfony/symfony' . | 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
symfony/symfony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 symfony/symfony to 8.0.12ステージング環境で 8.0.12 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。
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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-2026-45072 symfony Fixed in: 6.4.41+dfsg-0+deb13u1
- Ubuntu UBUNTU-CVE-2026-45072 symfony
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- patch github.com
- web github.com
- web github.com
- web github.com
- web symfony.com
- web github.com
- web github.com
- web github.com
- web github.com