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

> Attackers can steal sensitive credentials like cookies and authorization headers when PHP's HTTP stream wrapper follows cross-origin redirects.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Sep 2026
- **Updated:** 28 Sep 2026
- **Also known as:** AZL-104916, BELL-CVE-2026-91766, BIT-libphp-2026-91766, BIT-php-2026-91766, BIT-php-min-2026-91766, CLEANSTART-2026-GS69152, DEBIAN-CVE-2026-91766, ECHO-1af5-5cba-f445, MINI-26rq-522j-825q, MINI-4h8c-h6qx-99fh, MINI-4r85-fr2f-44p9, MINI-5qpv-g224-8vp7, MINI-5wwf-2c79-9fg3, MINI-gqx2-xw4q-8242, MINI-m9qw-c68h-jmgx, MINI-qgj6-3r9h-3mjx, UBUNTU-CVE-2026-91766

## What is CVE-2026-91766?

CVE-2026-91766 is a medium-severity vulnerability in Php Php, published on 25 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### 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 ).

Weakness: CWE-522 (Insufficiently Protected Credentials), CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2026-91766?

3 open source packages ship an affected version, including libphp, php and php-min. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `libphp` | Bitnami | From 8.2.0 | 8.2.34, 8.3.35, 8.4.26, 8.5.11 |
| `php` | Bitnami | From 8.2.0 | 8.2.34, 8.3.35, 8.4.26, 8.5.11 |
| `php-min` | Bitnami | From 8.2.0 | 8.2.34, 8.3.35, 8.4.26, 8.5.11 |

Products: Php Php.

## How do I fix CVE-2026-91766?

Upgrade libphp to a fixed version for your release line: 8.2.34, 8.3.35, 8.4.26 or 8.5.11.

## Is CVE-2026-91766 being exploited?

There is no known exploitation of CVE-2026-91766 in the wild and no public exploit code.

## Other vulnerabilities in Php Php

- [CVE-2012-2688](https://insights.sbomify.com/CVE-2012-2688/): Integer overflow in n/a (critical 10.0)
- [CVE-2012-2376](https://insights.sbomify.com/CVE-2012-2376/): Memory corruption in n/a (critical 10.0)
- [CVE-2011-3268](https://insights.sbomify.com/CVE-2011-3268/): Memory corruption in n/a (critical 10.0)
- [CVE-2009-4143](https://insights.sbomify.com/CVE-2009-4143/): Other in n/a (critical 10.0)
- [CVE-2008-5557](https://insights.sbomify.com/CVE-2008-5557/): Memory corruption in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-91766 and fix it if it is affected.

What it is: CVE-2026-91766 is a medium-severity vulnerability in Php Php, published on 25 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-91766 in the wild and no public exploit code.

Affected packages and fixed versions:
- libphp (Bitnami): affected from 8.2.0; fixed in 8.2.34, 8.3.35, 8.4.26, 8.5.11
- php (Bitnami): affected from 8.2.0; fixed in 8.2.34, 8.3.35, 8.4.26, 8.5.11
- php-min (Bitnami): affected from 8.2.0; fixed in 8.2.34, 8.3.35, 8.4.26, 8.5.11

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-91766/ (Markdown: https://insights.sbomify.com/CVE-2026-91766/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-91766
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-91766
- OSV: https://osv.dev/vulnerability/CVE-2026-91766

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-91766/
Summaries are generated and may contain mistakes; the official description above is the record.