CVE-2026-69246
Guzzle is an extensible PHP HTTP client. Prior to 7.15.2 and 8.0.1, Guzzle gives a transport the request URI as text and supplies the Host header separately. The cURL handlers set CURLOPT_URL to the URI exactly as written and push that Host into CURLOPT_HTTPHEADER; StreamHandler does the same through fopen(). libcurl then parses the authority itself, percent-decoding it and, on an IDN-capable build, applying IDNA mapping, and uses the result to resolve, connect, name the TLS peer and address a proxy CONNECT, while the supplied Host suppresses the aligned one libcurl would have generated. For a URI host written as 127.0.0.%31, filter_var() rejects the host as an IP literal, yet libcurl decodes it to 127.0.0.1 and reaches loopback with no DNS lookup while the server receives Host: 127.0.0.%31. An attacker who influences a fetched URI can therefore reach a host the application's checks excluded and read whatever the host exposes of the response. The same divergence moves Guzzle's own decisions onto a spelling the transport does not use: no_proxy selects proxy routing from the literal host, and RedirectMiddleware decides from it whether to strip Authorization and Cookie. Exploitation requires the application to build a request URI from untrusted input and to make a host decision before handing it to Guzzle. This issue is fixed in versions 7.15.2 and 8.0.1.
Scoring
- Severity
- HIGH
- CVSS base score
- 7.2
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
- EPSS probability
- 0.21%
- CWE
- CWE-180, CWE-436, CWE-918, CWE-941
- Published
- 2026-08-03
- Last modified
- 2026-08-04
Affected products
- guzzle guzzle
- guzzle guzzle
Weakness type
Related vulnerabilities
- CVE-2026-82736 — Ash.Type.CiString validates length and match constraints before case folding, allowing constraint bypass
- CVE-2026-82481 — The cohttp package before 6.3.0 for OCaml allows directory traversal.
- CVE-2026-76203 — CSS sanitizer bypass in Pentestify report themes allows forced outbound requests
- CVE-2026-73416 — jupyterlab: PyPI extension blocklist package-name canonicalization bypass
- CVE-2026-73420 — NextAuth.js: Email normalizer validates the address before Unicode normalization, allowing a homoglyph @ bypass
- CVE-2026-72917 — AnythingLLM: Password recovery accepts one recovery code twice after whitespace normalization
- CVE-2026-69245 — Guzzle: Noncanonical cookie domain keeps subdomain scope
- CVE-2026-62999 — Copier: Percent-encoded dot segments in template URLs can allow trusted-prefix escape (Incomplete fix for trust-prefix bypass)