CVE-2026-76172
highpriority · track · 0EPSS 0.002 · 14 %ileDEFRUSEPSS · scored 2026-10-27
fast-uri is a URI parser for Node.js. During parsing it runs a legacy decoding pass over the scheme component and never re-escapes the result, and serialization writes the scheme back out verbatim, unlike the host component which is re-escaped. As a result an input whose scheme carries percent-encoded slashes parses as a scheme with no authority, so the parsed host and error are both undefined, yet resolving or normalizing that same input emits a network-path reference whose authority is attacker-chosen and re-parses to that host. An application that allowlists on the parsed host, or treats a reference with no authority as safe to resolve against its base, gets the opposite of what it checked, giving an off-site redirect, server-side request forgery, or address-policy bypass. The legacy decoder also expands non-standard escape forms, widening the issue past upstream filters, and control characters in the scheme can reach the output as raw carriage return and line feed. The affected versions are 2.3.1 up to but not including 2.4.5, 3.0.0 up to but not including 3.1.6, and 4.0.0 up to but not including 4.1.3. The issue is fixed in 2.4.5, 3.1.6, and 4.1.3, which reject a scheme that is not valid after decoding. Users should upgrade to a patched version.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–7.5
ssvc
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weaknesses
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affected products (18)
Products and version ranges known to be affected.
advisories (4)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-3376Atlassian Bamboo, Bitbucket, Confluence, Fisheye/Crucible, Jira Software und Jira Service Management: Mehrere SchwachstellenDeutsch2026-09-15csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Atlassian Bamboo, Bitbucket, Confluence, Fisheye/Crucible, Jira Software und Jira Service Management ausnutzen, um beliebigen Programmcode auszuführen, Sicherheitsmaßnahmen zu umgehen, serverseitige Request-Forgery-Angriffe (SSRF) durchzuführen, Cross-Site-Scripting-Angriffe zu starten, sensible Informationen offenzulegen, Daten zu manipulieren oder Denial-of-Service-Zustände herbeizuführen.
- WID-SEC-W-2026-4056Atlassian Produkte (Bamboo, Bitbucket, Confluence, Crucible, Fisheye und Jira): Mehrere SchwachstellenDeutsch2026-10-20csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Atlassian Bamboo, Bitbucket, Confluence, Crucible, Fisheye und Jira ausnutzen, um Daten zu manipulieren, um seine Privilegien zu erhöhen, um einen Denial of Service Angriff durchzuführen, um Informationen offenzulegen, um einen Cross-Site Scripting Angriff durchzuführen, um Sicherheitsvorkehrungen zu umgehen und um beliebigen Programmcode auszuführen.
- GHSA-jqff-g426-hqxpfast-uri vulnerable to host confusion via percent-encoded scheme normalization2026-09-02ghsa · osvUS
### Impact `fast-uri` decodes percent-encoded characters in the scheme component with the legacy global `unescape()` and serializes the result back as raw characters, without re-escaping it or validating it as a scheme. A scheme that decodes to characters outside the RFC 3986 scheme grammar can therefore introduce structure the original input did not contain. For example, `%2f%2fevil.example:/pwn` parses with no authority (`parse().host` is `undefined`), but `resolve()` and `normalize()` return `//evil.example:/pwn`, which reparses with host `evil.example`. The `%uXXXX` form (`%u002f%u002fevil.example:/pwn`) produces the same result, and a scheme containing `%0d%0a` reaches the output as a raw CR LF. Applications that normalize or resolve untrusted URLs before a redirect check, host allowlist, or outbound request decision, especially ones that treat a missing authority as same-origin, can be steered to an attacker-chosen authority, and a normalized URI placed in a response header can carry an injected CR LF. ### Patches Upgrade to `fast-uri` >= 4.1.3, or >= 3.1.6 in the v3.x release line, or >= 2.4.5 in the v2.x release line. ### Workarounds None. Upgrade to the patched version.
- CERTFR-2026-AVI-1336Multiples vulnérabilités dans les produits IBMFrançais2026-10-16vendor · certfrFR
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references (2) nvd
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