Vulnerability in fast-uri (CVE-2026-6322)
Summary
Vulnerability in fast-uri (CVE-2026-6322). Data can be tampered with by attackers. Exploitable via evil.com. Mitigation: upgrade to 2.4.1 or later.
Original description
The description as published by the source.
Impact
fast-uri v3.1.1 and earlier decodes percent-encoded authority delimiters (%40 as @, %3A as :) inside the host component and serializes them back as raw characters. This changes the URI structure, turning a hostname into userinfo plus a different host.
For example, http://trusted.com%40evil.com/ normalizes to http://trusted.com@evil.com/, which reparses as host evil.com with userinfo trusted.com.
Applications that normalize untrusted URLs before host allowlist checks, redirect validation, or outbound request routing can be steered to a different authority than the original URL appeared to contain.
Patches
Upgrade to fast-uri >= 3.1.2, or if you are in the v2.x release line, v2.4.1
Workarounds
None. Upgrade to the patched version.
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-2026-6322 has been found in fast-uri.
Attackers can target a specific entry point like evil.com over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 7.5/10.
What to do: upgrade fast-uri to 2.4.1 or later.
If unsure, ask your IT team or search "fast-uri CVE-2026-6322" on the vendor's site.
CVE-2026-6322 (fast-uri) — CWE-140 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: evil.com / trusted.com
Patched: 2.4.1 — apply immediately
Workaround: None.
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-140) exists in fast-uri. Attackers reach the vulnerable code path via evil.com without authentication.
Check the vendor advisory for the affected versions of fast-uri. Attack surface: evil.com / trusted.com.
Severity: High (CVSS 7.5/10). Data can be tampered with by attackers.
Update to 2.4.1.
Workaround: None.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'fast-uri' . 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 'fast-uri' . | 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
fast-uriを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply temporary workaround mitigate
None.パッチが適用されるまでの応急処置として、None. を実施。回避策の副作用 (機能低下) を確認した上で。
-
3Apply patch patch
Upgrade fast-uri to 2.4.1ステージング環境で 2.4.1 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。
-
4Post-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-2026-6322 node-ajv
- Ubuntu UBUNTU-CVE-2026-6322 node-ajv
References
- package github.com
- web github.com
- web nvd.nist.gov
- web cna.openjsf.org
- web github.com
- web access.redhat.com
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- web bugzilla.redhat.com
- web security.access.redhat.com
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- web github.com
- web github.com
- web access.redhat.com
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- web access.redhat.com
- web access.redhat.com
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