guzzlehttp/guzzle security advisory

CVE-2026-69246: Guzzle: Noncanonical host can bypass host-based checks

CVE-2026-69246 is a high-severity SSRF vulnerability in the PHP package guzzlehttp/guzzle (CVSS 7.2), published 3 August 2026. It is fixed in 7.15.2 and 8.0.1, one per release line; earlier versions on each line are affected. It can be exploited without an account.

high 7.2 published 2026-08-03 · updated 2026-09-08

Affected versions: < 7.15.2
>= 8.0.0, < 8.0.1
Fixed in: 7.15.2, 8.0.1
Newest release: 8.3.1
Severity: High · CVSS 7.2
Type: Server-side request forgery (SSRF)
CWE-180, CWE-436, CWE-918, CWE-941
Exploited in the wild: Not on the CISA KEV list
checked 2026-11-04

Is your guzzlehttp/guzzle version affected?

Run composer show guzzlehttp/guzzle in your project, then enter the version. We check it against this and every other known guzzlehttp/guzzle advisory.

Who can exploit CVE-2026-69246

Access: No account. Anyone who can send a request to an app that uses the affected code.

CVSS vector (scored by GitHub): CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Your app is only exposed if it uses the affected part of guzzlehttp/guzzle. The advisory below says which part that is. If you are not sure, upgrade anyway: it costs less than finding out.

How to fix CVE-2026-69246 in guzzlehttp/guzzle

Find the installed version: composer show guzzlehttp/guzzle. If you never required it yourself, composer why guzzlehttp/guzzle shows which package pulls it in.
Update it: composer update guzzlehttp/guzzle --with-all-dependencies. You need the fixed version for your release line (7.15.2 and 8.0.1).
If Composer will not go that high, your composer.json constraint is holding it back. Widen it (for example "guzzlehttp/guzzle": "^8.0.1" if you can take that version), or upgrade the package that requires it.
Run composer audit. It reads the same advisory data and should no longer list CVE-2026-69246.
Commit composer.lock and deploy it. On the server, run composer install --no-dev from the lock file, not composer update.

If you cannot upgrade yet

General hardening for SSRF issues while the upgrade waits. None of it replaces the fix.

Block outbound requests from the app server to private ranges and cloud metadata (169.254.169.254) at the firewall.
Do not pass user-supplied URLs to the affected feature.
If your app does not use the affected feature, note that in your audit, but still plan the upgrade.

The CVE-2026-69246 advisory

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.

Description from the CVE record, published by GitHub (the CVE Numbering Authority), via the NVD entry for CVE-2026-69246. Advisory title: “Guzzle: Noncanonical host can bypass host-based checks”.

References

GitHub advisory GHSA-v5mv-p594-2x33 github.com
Fix commit 3aeea04 github.com
Fix commit 7441019 github.com
Pull request #3907 github.com
Pull request #3908 github.com
Release 7.15.2 github.com
Release 8.0.1 github.com

Other guzzlehttp/guzzle advisories

medium CVE-2026-69245: Guzzle: Noncanonical cookie domain keeps subdomain scope 2026-08-03
medium CVE-2026-67354: Guzzle: URI fragments disclosed in redirect Referer headers 2026-07-20
medium CVE-2026-67355: Guzzle: Host-only cookie scope is not preserved 2026-07-20
medium CVE-2026-67353: Guzzle: Unbounded response cookies risk denial of service 2026-07-20
medium CVE-2026-59883: Guzzle: Cookie Disclosure and Injection via IP-Address Domains 2026-07-20
medium CVE-2026-67339: Guzzle: Proxy-Authorization headers can be sent to origin servers 2026-07-20

Need help patching or upgrading? Laskyr does PHP and Laravel security fixes and upgrades. Tell us what you run and we reply with a plan and a price.

Ask about a fix

Where this data comes from

Affected and fixed versions: the Packagist security advisories API (GitHub Advisory Database and FriendsOfPHP), the same data composer audit uses. Synced 2026-11-03.
Description, score, weakness and references: NIST National Vulnerability Database (NVD), checked 2026-11-04. This product uses data from the NVD API but is not endorsed or certified by the NVD.
Exploited-in-the-wild status: the CISA Known Exploited Vulnerabilities catalog, checked 2026-11-04.
Compiled by Daniel Lasek at Laskyr from the sources above. The summary, “who can exploit it”, “how to fix it” and hardening sections are our plain-English reading of the record and are generated from it. The quoted description is the record's own text. Spot an error? Tell us.