# CVE-2023-26916: Null dereference in n/a

> A NULL pointer dereference in libyang allows attackers to cause a denial of service via crafted input to lys_parse_mem.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 3 Apr 2023
- **Updated:** 18 Feb 2025
- **Also known as:** AZL-25966, DEBIAN-CVE-2023-26916, GHSA-rgjq-f6gr-756j, UBUNTU-CVE-2023-26916, openSUSE-SU-2024:12836-1

## What is CVE-2023-26916?

CVE-2023-26916 is a medium-severity vulnerability in Fedoraproject Fedora, published on 3 Apr 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

libyang from v2.0.164 to v2.1.30 was discovered to contain a NULL pointer dereference via the function lys_parse_mem at lys_parse_mem.c.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2023-26916?

It affects 2 products.


Products: Cesnet Libyang, Fedoraproject Fedora.

## How do I fix CVE-2023-26916?

Upgrade to a fixed version.

## Is CVE-2023-26916 being exploited?

There is no known exploitation of CVE-2023-26916 in the wild and no public exploit code.

## Other vulnerabilities in Fedoraproject Fedora

- [CVE-2019-20393](https://insights.sbomify.com/CVE-2019-20393/): Memory corruption in n/a (high 8.8)
- [CVE-2019-20394](https://insights.sbomify.com/CVE-2019-20394/): Use after free in n/a (high 8.8)
- [CVE-2019-20397](https://insights.sbomify.com/CVE-2019-20397/): Memory corruption in n/a (high 8.8)
- [CVE-2019-19333](https://insights.sbomify.com/CVE-2019-19333/): Memory corruption in libyang (high 8.1)
- [CVE-2019-19334](https://insights.sbomify.com/CVE-2019-19334/): Memory corruption in libyang (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-26916 and fix it if it is affected.

What it is: CVE-2023-26916 is a medium-severity vulnerability in Fedoraproject Fedora, published on 3 Apr 2023. 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-2023-26916 in the wild and no public exploit code.

Affected product: Fedoraproject Fedora. 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-2023-26916/ (Markdown: https://insights.sbomify.com/CVE-2023-26916/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-26916
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-26916
- OSV: https://osv.dev/vulnerability/CVE-2023-26916

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-26916/
Summaries are generated and may contain mistakes; the official description above is the record.