Cross-origin credential leak in HTTP stream wrapper redirects (CVE-2026-91766) | HOL Guard CVE

Medium · CVSS 5.9CVE-2026-91766

Cross-origin credential leak in HTTP stream wrapper redirects

Answer in brief

CVE-2026-91766 records a Medium severity (CVSS 5.9) vulnerability in Cross-origin credential leak in HTTP stream wrapper redirects. The current sources do not mark it as known exploited. The current feed maps PHP Group/PHP (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 25, 2026Updated Sep 25, 2026Source checked Sep 25, 2026First seen by HOL Sep 25, 2026Material review Sep 25, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.9
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 5.9. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps PHP Group/PHP (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
PHP Group/PHPgeneric	>=8.2.* <8.2.34 \|\| >=8.3.* <8.3.35 \|\| >=8.4.* <8.4.26 \|\| >=8.5.* <8.5.11	8.2.34, 8.3.35, 8.4.26, 8.5.11

Recommended response

Check inventory. Check lockfiles and deployed manifests for PHP Group/PHP.
Review the reported fix. Update PHP Group/PHP to 8.2.34 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 25, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 25, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 25, 2026

Sources and claim methodology

GitHub security advisorygithub.com

Upstream source description

When the http:// stream wrapper follows a redirect it forwards the user-supplied Authorization, Cookie and Proxy-Authorization headers unchanged, even when the redirect target is a different host, a different port, or a downgrade from HTTPS to HTTP. A server that can steer a redirect therefore receives credentials that were only meant for the original origin. This is the same class of issue that libcurl fixed in 7.58.0 ( CVE-2018-1000007 https://github.com/advisories/GHSA-g7x2-hrfp-pv5f ).

Quoted source text, attributed separately from HOL analysis.