CVE-2026-91766

MEDIUM

5.9

CVSS v3

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 ).

CWE-200Information Exposure CWE-522

How to fix

Remediation Available

php8.2Debian

Fixed in:8.2.34-1~deb12u1CVE-2026-91766

php8.4Debian

Fixed in:8.4.26-1~deb13u1CVE-2026-91766

Fixed in:8.4.26-1CVE-2026-91766

apcu-panelRocky

Fixed in:0:5.1.18-1.module+el8.10.0+22485+a3539972.noarch::php:7.4RHSA-2026:87080

apcu-panelRed Hat / RHEL

Fixed in:0:5.1.18-1.module+el8.10.0+22485+a3539972.noarch::php:7.4RHSA-2026:87080

libzipRed Hat / RHEL

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.s390x::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.src::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.aarch64::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.ppc64le::php:7.4RHSA-2026:87080

libzipRocky

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.s390x::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.ppc64le::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.src::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.aarch64::php:7.4RHSA-2026:87080

libzip-debuginfoRed Hat / RHEL

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.aarch64::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.ppc64le::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.s390x::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.x86_64::php:7.4RHSA-2026:87080

libzip-debuginfoRocky

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.aarch64::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.s390x::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.ppc64le::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.x86_64::php:7.4RHSA-2026:87080

libzip-debugsourceRocky

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.ppc64le::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.aarch64::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.s390x::php:7.4RHSA-2026:87080

libzip-debugsourceRed Hat / RHEL

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.aarch64::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.s390x::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.ppc64le::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.x86_64::php:7.4RHSA-2026:87080

libzip-develRed Hat / RHEL

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.aarch64::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.ppc64le::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.s390x::php:7.4RHSA-2026:87080

libzip-develRocky

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.s390x::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.aarch64::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.ppc64le::php:7.4RHSA-2026:87080

libzip-toolsRed Hat / RHEL

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.aarch64::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.ppc64le::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.s390x::php:7.4RHSA-2026:87080

libzip-toolsRocky

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.ppc64le::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.aarch64::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.s390x::php:7.4RHSA-2026:87080

libzip-tools-debuginfoRed Hat / RHEL

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.ppc64le::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.s390x::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.aarch64::php:7.4RHSA-2026:87080

libzip-tools-debuginfoRocky

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.ppc64le::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.aarch64::php:7.4RHSA-2026:87080

Fixed in:0:1.6.1-1.module+el8.10.0+22485+a3539972.s390x::php:7.4RHSA-2026:87080

phpRocky

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.s390x::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.aarch64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.ppc64le::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.src::php:7.4RHSA-2026:87080

phpRed Hat / RHEL

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.src::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.s390x::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.ppc64le::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.aarch64::php:7.4RHSA-2026:87080

php-bcmathRocky

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.ppc64le::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.aarch64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.s390x::php:7.4RHSA-2026:87080

php-bcmathRed Hat / RHEL

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.s390x::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.ppc64le::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.aarch64::php:7.4RHSA-2026:87080

php-bcmath-debuginfoRocky

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.s390x::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.aarch64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.ppc64le::php:7.4RHSA-2026:87080

php-bcmath-debuginfoRed Hat / RHEL

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.aarch64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.s390x::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.ppc64le::php:7.4RHSA-2026:87080

php-cliRed Hat / RHEL

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.ppc64le::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.aarch64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.s390x::php:7.4RHSA-2026:87080

php-cliRocky

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.s390x::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.ppc64le::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.aarch64::php:7.4RHSA-2026:87080

php-cli-debuginfoRocky

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.aarch64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.s390x::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.ppc64le::php:7.4RHSA-2026:87080

php-cli-debuginfoRed Hat / RHEL

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.ppc64le::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.aarch64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.s390x::php:7.4RHSA-2026:87080

php-commonRed Hat / RHEL

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.ppc64le::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.aarch64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.s390x::php:7.4RHSA-2026:87080

php-commonRocky

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.s390x::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.ppc64le::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.aarch64::php:7.4RHSA-2026:87080

php-common-debuginfoRed Hat / RHEL

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.ppc64le::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.aarch64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.s390x::php:7.4RHSA-2026:87080

php-common-debuginfoRocky

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.ppc64le::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.s390x::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.x86_64::php:7.4RHSA-2026:87080

Fixed in:0:7.4.33-8.module+el8.10.0+25117+30337cca.aarch64::php:7.4RHSA-2026:87080

This vulnerability affects an unusually large number of packages. The highest-confidence fixes are shown above; the full list is longer. Check the referenced advisories for complete coverage.

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityNone

AvailabilityNone

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Exploit Intelligence

0.35%probability of exploitation in 30 days

27thpercentile

Low risk: more likely to be exploited than 27% of all known CVEs.

References

Exploit1

github.com

Related Vulnerabilities

Other CWE-200 (Information Exposure) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2024-24919	High	8.6	100%	KEV + Ransom	-
CVE-2020-14181	Medium	5.3	100%	-	Fix
CVE-2021-34429	Medium	5.3	99%	-	Fix
CVE-2018-11409	Medium	5.3	98%	-	-
CVE-2021-41277	Critical	10.0	97%	KEV	-
CVE-2016-2183	High	7.5	95%	-	Fix

Common questions

How do I fix CVE-2026-91766?

Published advisories record a fix for 208 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.

Is CVE-2026-91766 being actively exploited?

Not that we know of. CVE-2026-91766 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.35% is the estimated probability that it will be exploited in the next 30 days. That is higher than 27% of all scored CVEs.

How severe is CVE-2026-91766?

CVE-2026-91766 has a CVSS v3 base score of 5.9, rated moderate. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-91766 affect?

Published advisories record a fix for php8.2 (Debian), php8.4 (Debian), apcu-panel (Rocky), apcu-panel (Red Hat / RHEL), and 204 more. Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

Embed a live status badge for CVE-2026-91766

Markdown

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-10-23.