{"id":"CVE-2026-69246","state":"PUBLISHED","title":"Guzzle: Noncanonical host can bypass host-based checks","description":"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.","publishedAt":"2026-08-03T21:07:04.228Z","updatedAt":"2026-08-04T14:06:40.238Z","severity":{"score":7.2,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["guzzle guzzle"],"affected":[{"vendor":"guzzle","product":"guzzle","versions":[{"version":">= 8.0.0, < 8.0.1","status":"affected"},{"version":"< 7.15.2","status":"affected"}]}],"references":["https://github.com/guzzle/guzzle/security/advisories/GHSA-v5mv-p594-2x33","https://github.com/guzzle/guzzle/pull/3907","https://github.com/guzzle/guzzle/pull/3908","https://github.com/guzzle/guzzle/commit/3aeea0406aab88cbbd86531313d7cebf8ae149a4","https://github.com/guzzle/guzzle/commit/744101956d78b7c1384d0cbf379db13e859167bf","https://github.com/guzzle/guzzle/releases/tag/7.15.2","https://github.com/guzzle/guzzle/releases/tag/8.0.1"],"weaknesses":["CWE-180","CWE-436","CWE-918","CWE-941"],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/69xxx/CVE-2026-69246.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-69246","state":"PUBLISHED","datePublished":"2026-08-03T21:07:04.228Z","dateUpdated":"2026-08-04T14:06:40.238Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-08-03T19:54:19.852Z"},"containers":{"cna":{"title":"Guzzle: Noncanonical host can bypass host-based checks","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"guzzle","product":"guzzle","versions":[{"version":">= 8.0.0, < 8.0.1","status":"affected"},{"version":"< 7.15.2","status":"affected"}]}],"references":[{"url":"https://github.com/guzzle/guzzle/security/advisories/GHSA-v5mv-p594-2x33","name":"https://github.com/guzzle/guzzle/security/advisories/GHSA-v5mv-p594-2x33","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/guzzle/guzzle/pull/3907","name":"https://github.com/guzzle/guzzle/pull/3907","tags":["x_refsource_MISC"]},{"url":"https://github.com/guzzle/guzzle/pull/3908","name":"https://github.com/guzzle/guzzle/pull/3908","tags":["x_refsource_MISC"]},{"url":"https://github.com/guzzle/guzzle/commit/3aeea0406aab88cbbd86531313d7cebf8ae149a4","name":"https://github.com/guzzle/guzzle/commit/3aeea0406aab88cbbd86531313d7cebf8ae149a4","tags":["x_refsource_MISC"]},{"url":"https://github.com/guzzle/guzzle/commit/744101956d78b7c1384d0cbf379db13e859167bf","name":"https://github.com/guzzle/guzzle/commit/744101956d78b7c1384d0cbf379db13e859167bf","tags":["x_refsource_MISC"]},{"url":"https://github.com/guzzle/guzzle/releases/tag/7.15.2","name":"https://github.com/guzzle/guzzle/releases/tag/7.15.2","tags":["x_refsource_MISC"]},{"url":"https://github.com/guzzle/guzzle/releases/tag/8.0.1","name":"https://github.com/guzzle/guzzle/releases/tag/8.0.1","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.2,"baseSeverity":"HIGH","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-180","lang":"en","description":"CWE-180: Incorrect Behavior Order: Validate Before Canonicalize","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-436","lang":"en","description":"CWE-436: Interpretation Conflict","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-918","lang":"en","description":"CWE-918: Server-Side Request Forgery (SSRF)","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-941","lang":"en","description":"CWE-941: Incorrectly Specified Destination in a Communication Channel","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-03T21:07:04.228Z"},"source":{"advisory":"GHSA-v5mv-p594-2x33","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-04T14:06:26.614857Z","id":"CVE-2026-69246","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-04T14:06:40.238Z"}}]}}}