Vulnerability · Published Sep 25, 2026 · Assigned by php

CVE-2026-91766Cross-origin credential leak in HTTP stream wrapper redirects

Medium 5.9

In plain English

A medium-severity information exposure in PHP from PHP Group. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 21% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.9Medium
Exploit odds (30 days)0.3%top 78.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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 ).

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:8apcu-panel5.1.18-1.module_el8.6.0+2750+78feabcbALSA-2026:87080
AlmaLinux:8libzip1.6.1-1.module_el8.6.0+3239+bedf0508ALSA-2026:87080
AlmaLinux:8libzip1.6.1-1.module_el8.6.0+2750+78feabcbALSA-2026:87080
AlmaLinux:8libzip1.6.1-1.module_el8.10.0+3935+28808425ALSA-2026:87080
AlmaLinux:8libzip-devel1.6.1-1.module_el8.6.0+2750+78feabcbALSA-2026:87080
AlmaLinux:8libzip-devel1.6.1-1.module_el8.10.0+3935+28808425ALSA-2026:87080
AlmaLinux:8libzip-devel1.6.1-1.module_el8.6.0+3239+bedf0508ALSA-2026:87080
AlmaLinux:8libzip-tools1.6.1-1.module_el8.10.0+3935+28808425ALSA-2026:87080
AlmaLinux:8libzip-tools1.6.1-1.module_el8.6.0+3239+bedf0508ALSA-2026:87080
AlmaLinux:8php7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-bcmath7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-cli7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-common7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-dba7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-dbg7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-devel7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-embedded7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-enchant7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-ffi7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-fpm7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-gd7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-gmp7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-intl7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-json7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-ldap7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-mbstring7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-mysqlnd7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-odbc7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-opcache7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-pdo7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-pear1:1.10.13-1.module_el8.10.0+3935+28808425ALSA-2026:87080
AlmaLinux:8php-pecl-apcu5.1.18-1.module_el8.10.0+3935+28808425ALSA-2026:87080
AlmaLinux:8php-pecl-apcu5.1.18-1.module_el8.6.0+2750+78feabcbALSA-2026:87080
AlmaLinux:8php-pecl-apcu-devel5.1.18-1.module_el8.6.0+2750+78feabcbALSA-2026:87080
AlmaLinux:8php-pecl-apcu-devel5.1.18-1.module_el8.10.0+3935+28808425ALSA-2026:87080
AlmaLinux:8php-pecl-rrd2.0.1-1.module_el8.6.0+2750+78feabcbALSA-2026:87080
AlmaLinux:8php-pecl-rrd2.0.1-1.module_el8.6.0+3239+bedf0508ALSA-2026:87080
AlmaLinux:8php-pecl-rrd2.0.1-1.module_el8.10.0+3935+28808425ALSA-2026:87080
AlmaLinux:8php-pecl-xdebug2.9.5-1.module_el8.6.0+3239+bedf0508ALSA-2026:87080
AlmaLinux:8php-pecl-xdebug2.9.5-1.module_el8.6.0+2750+78feabcbALSA-2026:87080
AlmaLinux:8php-pecl-zip1.18.2-1.module_el8.6.0+2750+78feabcbALSA-2026:87080
AlmaLinux:8php-pecl-zip1.18.2-1.module_el8.10.0+3935+28808425ALSA-2026:87080
AlmaLinux:8php-pecl-zip1.18.2-1.module_el8.6.0+3239+bedf0508ALSA-2026:87080
AlmaLinux:8php-pgsql7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-process7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-snmp7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-soap7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-xml7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
AlmaLinux:8php-xmlrpc7.4.33-8.module_el8.10.0+4321+cf5fd4bbALSA-2026:87080
Alpine:v3.22php828.2.35-r0ALPINE-CVE-2026-91766
Alpine:v3.22php838.3.36-r0ALPINE-CVE-2026-91766
Alpine:v3.23php838.3.36-r0ALPINE-CVE-2026-91766
Alpine:v3.24php838.3.35-r0ALPINE-CVE-2026-91766
Alpine:v3.22php848.4.27-r0ALPINE-CVE-2026-91766
Alpine:v3.23php848.4.27-r0ALPINE-CVE-2026-91766
Alpine:v3.24php848.4.26-r0ALPINE-CVE-2026-91766
Alpine:v3.23php858.5.12-r0ALPINE-CVE-2026-91766
Alpine:v3.24php858.5.11-r0ALPINE-CVE-2026-91766
Debian:12php8.28.2.34-1~deb12u1DEBIAN-CVE-2026-91766
Debian:13php8.48.4.26-1~deb13u1DEBIAN-CVE-2026-91766
Debian:14php8.48.4.26-1DEBIAN-CVE-2026-91766
Rocky Linux:8libzip0:1.6.1-1.module+el8.10.0+1604+6558efc7RLSA-2026:87080
Rocky Linux:8libzip0:1.6.1-1.module+el8.10.0+1912+72767185RLSA-2026:87080
Rocky Linux:8php0:7.4.33-8.module+el8.10.0+40393+c071e357RLSA-2026:87080
Rocky Linux:8php-pear1:1.10.13-1.module+el8.10.0+1605+02e07af7RLSA-2026:87080
Rocky Linux:8php-pear1:1.10.13-1.module+el8.10.0+1912+72767185RLSA-2026:87080
Rocky Linux:8php-pear1:1.10.13-1.module+el8.10.0+1604+6558efc7RLSA-2026:87080
Rocky Linux:8php-pecl-apcu0:5.1.18-1.module+el8.10.0+1604+6558efc7RLSA-2026:87080
Rocky Linux:8php-pecl-apcu0:5.1.18-1.module+el8.10.0+1912+72767185RLSA-2026:87080
Rocky Linux:8php-pecl-rrd0:2.0.1-1.module+el8.10.0+1604+6558efc7RLSA-2026:87080
Rocky Linux:8php-pecl-rrd0:2.0.1-1.module+el8.4.0+414+2e7afcddRLSA-2026:87080
Rocky Linux:8php-pecl-rrd0:2.0.1-1.module+el8.10.0+1912+72767185RLSA-2026:87080
Rocky Linux:8php-pecl-xdebug0:2.9.5-1.module+el8.10.0+1912+72767185RLSA-2026:87080
Rocky Linux:8php-pecl-xdebug0:2.9.5-1.module+el8.10.0+1604+6558efc7RLSA-2026:87080
Rocky Linux:8php-pecl-zip0:1.18.2-1.module+el8.10.0+1604+6558efc7RLSA-2026:87080
Rocky Linux:8php-pecl-zip0:1.18.2-1.module+el8.10.0+1912+72767185RLSA-2026:87080
Ubuntu:22.04:LTSphp8.18.1.2-1ubuntu2.27USN-8936-1
Ubuntu:22.04:LTSphp8.18.1.2-1ubuntu2.27UBUNTU-CVE-2026-91766
Ubuntu:24.04:LTSphp8.38.3.6-0ubuntu0.24.04.12UBUNTU-CVE-2026-91766
Ubuntu:24.04:LTSphp8.38.3.6-0ubuntu0.24.04.12USN-8936-1
Ubuntu:26.04:LTSphp8.58.5.4-0ubuntu1.4UBUNTU-CVE-2026-91766
Ubuntu:26.04:LTSphp8.58.5.4-0ubuntu1.4USN-8936-1
Ubuntu:26.10php8.58.5.9-0ubuntu2UBUNTU-CVE-2026-91766
Ubuntu:26.10php8.58.5.9-0ubuntu2USN-8936-1

Affected products (as reported)

VendorProductVersions
PHP Group PHP 8.2.* – before 8.2.348.3.* – before 8.3.358.4.* – before 8.4.268.5.* – before 8.5.11

Weakness: CWE-200, CWE-522 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

References