# CVE-2026-93312: Freedesktop Poppler JBIG2Stream.cc rewind null pointer dereference

> Remote attackers can cause a denial of service via null pointer dereference in Poppler's JBIG2Stream, requiring an upgrade to fix.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 18 Sep 2026
- **Updated:** 22 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-93312, ECHO-16f1-c40a-5bf3, GHSA-mm25-wh7f-mmv7, UBUNTU-CVE-2026-93312

## What is CVE-2026-93312?

CVE-2026-93312 is a medium-severity vulnerability in Freedesktop Poppler, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

A flaw has been found in Freedesktop Poppler 26.07.0. Impacted is the function JBIG2Stream::rewind of the file poppler/JBIG2Stream.cc. This manipulation causes null pointer dereference. It is possible to initiate the attack remotely. The exploit has been published and may be used. Upgrading to version 26.08.0 is recommended to address this issue. Patch name: 5e49250f13b0390edeb3f90eb4c02c9941f97067. Upgrading the affected component is advised.

Weakness: CWE-476 (NULL Pointer Dereference), CWE-404 (Improper Resource Shutdown or Release)

## Which versions are affected by CVE-2026-93312?


## How do I fix CVE-2026-93312?

Upgrade to a fixed version.

## Is CVE-2026-93312 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-93312 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93312 and fix it if it is affected.

What it is: CVE-2026-93312 is a medium-severity vulnerability in Freedesktop Poppler, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-93312 exists.

Affected product: Freedesktop Poppler. 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-2026-93312/ (Markdown: https://insights.sbomify.com/CVE-2026-93312/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93312
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93312
- OSV: https://osv.dev/vulnerability/CVE-2026-93312

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93312/
Summaries are generated and may contain mistakes; the official description above is the record.