Vulnerability in @fastify/accepts-serializer (CVE-2026-7768)
Summary
Vulnerability in @fastify/accepts-serializer (CVE-2026-7768). Risk of unauthorized operations or information disclosure. Exploitable via Accept. Mitigation: upgrade to 6.0.4 or later.
Original description
The description as published by the source.
@fastify/accepts-serializer cached serializer-selection results keyed by the request Accept header without a size limit or eviction policy. A remote unauthenticated client could send many distinct but matching Accept header variants to make the cache grow unbounded, eventually exhausting the Node.js heap and crashing the process. Versions <= 6.0.3 are affected. Update to 6.0.4 or later, which bounds the cache via an LRU with a default size of 100 entries, configurable through the new cacheSize plugin option.
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-2026-7768 has been found in @fastify/accepts-serializer.
Attackers can target a specific entry point like Accept over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: upgrade @fastify/accepts-serializer to 6.0.4 or later.
If unsure, ask your IT team or search "@fastify/accepts-serializer CVE-2026-7768" on the vendor's site.
CVE-2026-7768 (@fastify/accepts-serializer) — CWE-770 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: Accept / cacheSize
Patched: 6.0.4 — 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-770) exists in @fastify/accepts-serializer. Attackers reach the vulnerable code path via Accept without authentication.
Check the vendor advisory for the affected versions of @fastify/accepts-serializer. Attack surface: Accept / cacheSize.
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.
Update to 6.0.4.
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 '@fastify/accepts-serializer' . 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 '@fastify/accepts-serializer' . | 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
@fastify/accepts-serializer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 @fastify/accepts-serializer to 6.0.4ステージング環境で 6.0.4 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
References
- advisory github.com
- advisory nvd.nist.gov
- advisory cna.openjsf.org
- advisory github.com
- package github.com
- web github.com