# CVE-2026-89161: Use after free in PCRE2

> A use-after-free vulnerability in PCRE2 allows attackers to execute arbitrary code or cause denial of service via crafted regex patterns.

- **Severity:** High 7.4 (`CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 11 Sep 2026
- **Updated:** 11 Sep 2026
- **Also known as:** ALPINE-CVE-2026-89161, AZL-100053, AZL-101766, AZL-101790, AZL-101802, AZL-101823, BELL-CVE-2026-89161, DEBIAN-CVE-2026-89161, ECHO-4e33-89ce-0def, GHSA-7g92-94jm-fx5f, MINI-6m6x-f6qr-qxxm, ROOT-OS-ALPINE-315-CVE-2026-89161, UBUNTU-CVE-2026-89161

## What is CVE-2026-89161?

CVE-2026-89161 is a high-severity use after free vulnerability in PCRE2, published on 11 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In PCRE2 before 10.48, pcre2_jit_match mishandles a previously copied subject being passed in as a context. An incorrect free operation can occur.

Weakness: CWE-590 (Free of Memory not on the Heap)

## Which versions are affected by CVE-2026-89161?

It affects 1 product.


Products: Pcre Pcre2.

## How do I fix CVE-2026-89161?

Upgrade to a fixed version.

## Is CVE-2026-89161 being exploited?

There is no known exploitation of CVE-2026-89161 in the wild and no public exploit code.

## Other vulnerabilities in PCRE2

- [CVE-2017-8786](https://insights.sbomify.com/CVE-2017-8786/): Memory corruption in n/a (critical 9.8)
- [CVE-2017-8399](https://insights.sbomify.com/CVE-2017-8399/): Memory corruption in n/a (critical 9.8)
- [CVE-2022-41409](https://insights.sbomify.com/CVE-2022-41409/): Integer overflow in n/a (high 7.5)
- [CVE-2025-58050](https://insights.sbomify.com/CVE-2025-58050/): PCRE2: heap-buffer-overflow read in match_ref due to missing boundary restoration in SCS (medium 6.9)
- [CVE-2026-89158](https://insights.sbomify.com/CVE-2026-89158/): Integer overflow in PCRE2 (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89161 and fix it if it is affected.

What it is: CVE-2026-89161 is a high-severity use after free vulnerability in PCRE2, published on 11 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-2026-89161 in the wild and no public exploit code.

Affected product: PCRE2. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-89161/ (Markdown: https://insights.sbomify.com/CVE-2026-89161/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89161
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89161
- OSV: https://osv.dev/vulnerability/CVE-2026-89161

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89161/
Summaries are generated and may contain mistakes; the official description above is the record.