CVE-2026-67354

guzzlehttp/guzzle before 7.15.1 URI Fragment Disclosure via Referer

MEDIUM
5.9
CVSS Score
Published: August 1, 2026 at 12:22 PM UTC
Updated: October 8, 2026 at 04:17 PM UTC
2 products affected across 2 vendorsGuzzleGuzzle

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Severity
MEDIUM5.9
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 7.15.1
Affected range stops below 7.15.1, so it looks safe — our inference, not a vendor statement
0 ≤ v < 7.15.10
Vendor states this is fixed in 7.15.1 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.9MEDIUMVulnCheck
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-201

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