GHSA-mqq9-gxg5-m58g: Duplicate Advisory Guzzle: URI Fragments Disclosed Vulnerability

HIGH
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CVSS 5.9
CWE-201
Published
Advisory Summary

GHSA-mqq9-gxg5-m58g is a HIGH (CVSS 5.9) guzzle: uri fragments disclosed vulnerability (CWE-201: Insertion of Sensitive Information Into Sent Data) affecting Duplicate Advisory libraries in the Packagist ecosystem. The issue involves guzzle: uri fragments disclosed in redirect referer headers. Remediation is available in the latest vendor maintenance releases.

GHSA-mqq9-gxg5-m58g at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-mqq9-gxg5-m58g
Severity HIGH
CVSS v3.1 Base Score 5.9
CWE Classification CWE-201: Insertion of Sensitive Information Into Sent Data
Affected Product Duplicate Advisory
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 5.9

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity None (I:N)
Availability None (A:N)

How to Fix GHSA-mqq9-gxg5-m58g

To remediate this vulnerability, upgrade all affected Duplicate Advisory dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

guzzlehttp/guzzle fixed: Latest secure release 
Upgrade guzzlehttp/guzzle to Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for guzzlehttp/guzzle

How to Check if You Are Affected

To determine whether your application is affected by GHSA-mqq9-gxg5-m58g, inspect your project dependencies for Duplicate Advisory:

inspect dependencies for guzzlehttp/guzzle

Analyze the terminal output to locate any version of Duplicate Advisory in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-201: Insertion of Sensitive Information Into Sent Data, where the code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor. In Duplicate Advisory, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

## Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-h95v-h523-3mw8. This link is maintained to preserve external references. ## Original 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.

GHSA-mqq9-gxg5-m58g Affected Duplicate Advisory Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
guzzlehttp/guzzle
 Packagist

References

GitHub Advisory / Wiki ADVISORY
https://github.com/guzzle/guzzle/security/advisories/GHSA-h95v-h523-3mw8
NVD — GHSA-mqq9-gxg5-m58g NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-67354
www.vulncheck.com/advisories/guzzleht... WEB
https://www.vulncheck.com/advisories/guzzlehttp-guzzle-before-uri-fragment-disclosure-via-referer

Frequently Asked Questions

What is GHSA-mqq9-gxg5-m58g?
GHSA-mqq9-gxg5-m58g is a security vulnerability in Duplicate Advisory involving Guzzle: URI fragments disclosed in redirect Referer headers under CWE-201: Insertion of Sensitive Information Into Sent Data.
Which Duplicate Advisory versions are affected?
Affected versions include releases prior to current release patches across affected packages: guzzlehttp/guzzle.
What version fixes GHSA-mqq9-gxg5-m58g?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is guzzlehttp/guzzle affected?
Yes, guzzlehttp/guzzle is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of GHSA-mqq9-gxg5-m58g?
GHSA-mqq9-gxg5-m58g has a CVSS v3.1 base score of 5.9 (HIGH) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with GHSA-mqq9-gxg5-m58g?
GHSA-mqq9-gxg5-m58g is classified under CWE-201: Insertion of Sensitive Information Into Sent Data (The code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor.).
How can I check Packagist dependencies for GHSA-mqq9-gxg5-m58g?
Run the dependency tree command: 'inspect dependencies for guzzlehttp/guzzle'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-mqq9-gxg5-m58g",
  "modified" : "2026-08-04T12:53:33Z",
  "published" : "2026-08-01T15:30:30Z",
  "withdrawn" : "2026-08-04T12:53:33Z",
  "aliases" : [ ],
  "summary" : "Duplicate Advisory: Guzzle: URI fragments disclosed in redirect Referer headers",
  "details" : "## Duplicate Advisory\n\nThis advisory has been withdrawn because it is a duplicate of GHSA-h95v-h523-3mw8. This link is maintained to preserve external references.\n\n## Original Description\n\nguzzlehttp/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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "guzzlehttp/guzzle"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "< 7.15.1"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/guzzle/guzzle/security/advisories/GHSA-h95v-h523-3mw8"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-67354"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/guzzlehttp-guzzle-before-uri-fragment-disclosure-via-referer"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-201" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-04T12:53:33Z",
    "nvd_published_at" : "2026-08-01T13:17:06Z"
  }
}