# CVE-2026-91767: Heap-buffer-overflow in php_openssl_matches_wildcard_name on crafted server cert wildcard CN

> A malicious TLS server can trigger a heap buffer overflow in PHP's OpenSSL extension, potentially causing denial of service or arbitrary code execution.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Sep 2026
- **Updated:** 28 Sep 2026
- **Also known as:** AZL-104922, BELL-CVE-2026-91767, BIT-libphp-2026-91767, BIT-php-2026-91767, BIT-php-min-2026-91767, CLEANSTART-2026-JC19240, DEBIAN-CVE-2026-91767, ECHO-3b9e-4caf-d695, MINI-34hm-g6fr-98rp, MINI-4f22-3c7h-qh22, MINI-4qgq-x6pg-5cgp, MINI-765p-gm58-rrrv, MINI-j96g-f62q-x352, MINI-jm6w-q8r7-4qrx, MINI-pwmq-8hj2-9pqj, MINI-q3qx-9c8q-5j75, UBUNTU-CVE-2026-91767

## What is CVE-2026-91767?

CVE-2026-91767 is a medium-severity memory corruption vulnerability in Php Php, published on 25 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

php_openssl_matches_wildcard_name() in ext/openssl/xp_ssl.c underflows the length argument passed to memchr() when a TLS server certificate presents a wildcard name whose literal characters are together longer than the hostname being verified. A malicious server presenting such a certificate makes the PHP client read up to SIZE_MAX bytes past the end of a heap allocation. The path is reachable from any default client stream, because verify_peer_name is enabled by default.

Weakness: CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2026-91767?

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-2026-91767?

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-2026-91767 being exploited?

There is no known exploitation of CVE-2026-91767 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-2026-91767 and fix it if it is affected.

What it is: CVE-2026-91767 is a medium-severity memory corruption vulnerability in Php Php, published on 25 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-91767 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-2026-91767/ (Markdown: https://insights.sbomify.com/CVE-2026-91767/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-91767
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-91767
- OSV: https://osv.dev/vulnerability/CVE-2026-91767

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-91767/
Summaries are generated and may contain mistakes; the official description above is the record.