CVE-2026-67354 guzzlehttp/guzzle before 7.15.1 URI Fragment Disclosure via Referer
Attackers can read sensitive URI fragments from Referer headers if redirect referer logging is enabled, exposing tokens or secrets.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-67354?
CVE-2026-67354 is a high-severity vulnerability in guzzle, published on 1 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
guzzlehttp/guzzle versions before 7.15.1 contain an information disclosure vulnerability in RedirectMiddleware. When the optional allow_redirects.referer setting is enabled, the middleware copies the URI fragment (the portion after '#') from the referring request into the generated Referer header when following a same-scheme redirect (e.g., HTTPS to HTTPS). An attacker who controls the redirect destination can read this fragment from the incoming Referer header, potentially disclosing one-time login secrets, access tokens, state values, or other sensitive client data to a server never meant to receive it. The referer setting is disabled by default. Fixed in 7.15.1, which strips the fragment before generating the Referer value.
Weakness: CWE-201
Which versions are affected by CVE-2026-67354?
2 open source packages ship an affected version, including guzzlehttp/guzzle.
| Package | Affected | Fixed in |
|---|---|---|
guzzlehttp/guzzle Packagist | All versions | 7.15.1 |
guzzlehttp/guzzle Packagist | All versions | 7.15.1 |
How do I fix CVE-2026-67354?
Upgrade guzzlehttp/guzzle to 7.15.1 or later.
Is CVE-2026-67354 being exploited?
There is no known exploitation of CVE-2026-67354 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-67354, GHSA-h95v-h523-3mw8, MINI-32hp-qmpm-vfjj, MINI-53p4-q2mr-557q, MINI-5rwf-pjqh-788c, MINI-7pw7-cxgp-w69w and 5 more.