# CVE-2026-74860: Libxml2: double-free/uaf in libxml2 python bindings

> A double-free vulnerability in libxml2 Python bindings allows remote attackers to cause a denial of service via crafted XML documents.

- **Severity:** High 8.5 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 8 Sep 2026
- **Updated:** 29 Oct 2026
- **Also known as:** AZL-100941, BELL-CVE-2026-74860, CLSA-2026-1790786185, CLSA-2026-1790833998, CLSA-2026-1791280039, CLSA-2026-1791372460, CLSA-2026-1791489916, CLSA-2026-1791493216, CLSA-2026-1791551729, DEBIAN-CVE-2026-74860, ECHO-88ec-e122-3747, GHSA-8626-cqqj-mfff, ROOT-OS-DEBIAN-12-CVE-2026-74860, ROOT-OS-DEBIAN-13-CVE-2026-74860, UBUNTU-CVE-2026-74860

## What is CVE-2026-74860?

CVE-2026-74860 is a high-severity use after free vulnerability in Cert Manager support for Red Hat OpenShift release 1.20, published on 8 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A flaw was found in libxml2 with Python bindings enabled. A remote attacker could exploit this vulnerability by providing a specially crafted XML document containing a Document Type Definition (DTD) with enumerated attribute values. This triggers a double-free error in the SAX attributeDecl callback handler, where a string is freed twice. This flaw can lead to a denial of service (DoS) due to a reproducible crash in Python applications using the libxml2 SAX bindings.

Weakness: CWE-763 (Release of Invalid Pointer or Reference)

## Which versions are affected by CVE-2026-74860?


## How do I fix CVE-2026-74860?

Apply the vendor's patch.

## Is CVE-2026-74860 being exploited?

There is no known exploitation of CVE-2026-74860 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74860 and fix it if it is affected.

What it is: CVE-2026-74860 is a high-severity use after free vulnerability in Cert Manager support for Red Hat OpenShift release 1.20, published on 8 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-74860 in the wild and no public exploit code.

Affected product: Cert Manager support for Red Hat OpenShift release 1.20. 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-2026-74860/ (Markdown: https://insights.sbomify.com/CVE-2026-74860/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74860
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74860
- OSV: https://osv.dev/vulnerability/CVE-2026-74860

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-74860/
Summaries are generated and may contain mistakes; the official description above is the record.