# CVE-2026-44742: Postorius is vulnerable to XSS

> Attackers can execute arbitrary scripts in the Postorius held messages pop-up due to unescaped HTML in message subjects, potentially compromising user accounts.

- **Severity:** High 7.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 7 May 2026
- **Updated:** 25 May 2026
- **Also known as:** DEBIAN-CVE-2026-44742, GHSA-r7c9-7pjq-hmm8, PYSEC-2026-2891, UBUNTU-CVE-2026-44742, USN-8323-1, openSUSE-SU-2026:11539-1

## What is CVE-2026-44742?

CVE-2026-44742 is a high-severity cross-site scripting vulnerability in Postorius, published on 7 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Postorius through 1.3.13 does not escape HTML in the message subject when rendering it in the Held messages pop-up, as exploited in the wild in May 2026.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-44742?

3 open source packages ship an affected version, including postorius. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `postorius` | PyPI | All versions to 1.3.13 | None |
| `postorius` | PyPI | All versions to 1.3.13 | None |
| `postorius` | PyPI | All versions to 1.3.13 | None |
| `python-postorius` | openSUSE:Tumbleweed | All versions | 1.3.13-8.1 |

Products: Postorius Project Postorius.

## How do I fix CVE-2026-44742?

Upgrade to a fixed version.

## Is CVE-2026-44742 being exploited?

There is no known exploitation of CVE-2026-44742 in the wild and no public exploit code.

## Other vulnerabilities in Postorius

- [CVE-2021-40347](https://insights.sbomify.com/CVE-2021-40347/): GNU Mailman Postorius Access Control Issues (medium 5.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-44742 and fix it if it is affected.

What it is: CVE-2026-44742 is a high-severity cross-site scripting vulnerability in Postorius, published on 7 May 2026. 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-2026-44742 in the wild and no public exploit code.

Affected packages and fixed versions:
- postorius (PyPI): affected all versions up to 1.3.13; no fix listed
- postorius (PyPI): affected all versions up to 1.3.13; no fix listed
- postorius (PyPI): affected all versions up to 1.3.13; no fix listed

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-2026-44742/ (Markdown: https://insights.sbomify.com/CVE-2026-44742/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-44742
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-44742
- OSV: https://osv.dev/vulnerability/CVE-2026-44742

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-44742/
Summaries are generated and may contain mistakes; the official description above is the record.