Log in Start free

Vulnerability · Published Aug 1, 2026 · Assigned by VulnCheck

CVE-2026-67354guzzlehttp/guzzle before 7.15.1 URI Fragment Disclosure via Referer

Medium 5.9

In plain English

A medium-severity security flaw in guzzle from guzzle. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 31% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.9Medium
Exploit odds (30 days)0.4%top 68.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12guzzleno fix listedDEBIAN-CVE-2026-67354
Debian:13guzzleno fix listedDEBIAN-CVE-2026-67354
Debian:14guzzle7.15.1-1DEBIAN-CVE-2026-67354
Packagistguzzlehttp/guzzle7.15.1GHSA-h95v-h523-3mw8
Ubuntu:24.04:LTSguzzleno fix listedUBUNTU-CVE-2026-67354
Ubuntu:26.04:LTSguzzleno fix listedUBUNTU-CVE-2026-67354
Ubuntu:26.10guzzleno fix listedUBUNTU-CVE-2026-67354

Affected products (as reported)

VendorProductVersions
guzzle guzzle 0 – before 7.15.1

Weakness: CWE-201 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

References