# CVE-2026-22245: Mastodon has SSRF Protection bypass

> Attackers can bypass SSRF protections to access local network resources via crafted IP addresses in Mastodon.

- **Severity:** High 7.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **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 Jan 2026
- **Updated:** 8 Jan 2026
- **Also known as:** BIT-mastodon-2026-22245, GHSA-xfrj-c749-jxxq

## What is CVE-2026-22245?

CVE-2026-22245 is a high-severity server-side request forgery vulnerability in mastodon, published on 8 Jan 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Mastodon is a free, open-source social network server based on ActivityPub. By nature, Mastodon performs a lot of outbound requests to user-provided domains. Mastodon, however, has some protection mechanism to disallow requests to local IP addresses (unless specified in `ALLOWED_PRIVATE_ADDRESSES`) to avoid the "confused deputy" problem. The list of disallowed IP address ranges was lacking some IP address ranges that can be used to reach local IP addresses. An attacker can use an IP address in the affected ranges to make Mastodon perform HTTP requests against loopback or local network hosts, potentially allowing access to otherwise private resources and services. This is fixed in Mastodon v4.5.4, v4.4.11, v4.3.17 and v4.2.29.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-22245?

1 open source package ship an affected version, including mastodon. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `mastodon` | Bitnami | All versions | 4.2.29, 4.3.17, 4.4.11, 4.5.4 |

Products: Joinmastodon Mastodon.

## How do I fix CVE-2026-22245?

Upgrade mastodon to a fixed version for your release line: 4.2.29, 4.3.17, 4.4.11 or 4.5.4.

## Is CVE-2026-22245 being exploited?

There is no known exploitation of CVE-2026-22245 in the wild and no public exploit code.

## Other vulnerabilities in mastodon

- [CVE-2023-36460](https://insights.sbomify.com/CVE-2023-36460/): Mastodon vulnerable to arbitrary file creation through media attachments (critical 10.0)
- [CVE-2022-2166](https://insights.sbomify.com/CVE-2022-2166/): Improper Restriction of Excessive Authentication Attempts in mastodon/mastodon (critical 9.8)
- [CVE-2022-24307](https://insights.sbomify.com/CVE-2022-24307/): Missing authorization in n/a (critical 9.8)
- [CVE-2018-21018](https://insights.sbomify.com/CVE-2018-21018/): Auth bypass in n/a (critical 9.8)
- [CVE-2024-23832](https://insights.sbomify.com/CVE-2024-23832/): Mastodon Remote user impersonation and takeover (critical 9.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-22245 and fix it if it is affected.

What it is: CVE-2026-22245 is a high-severity server-side request forgery vulnerability in mastodon, published on 8 Jan 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-2026-22245 in the wild and no public exploit code.

Affected packages and fixed versions:
- mastodon (Bitnami): affected all versions; fixed in 4.2.29, 4.3.17, 4.4.11, 4.5.4

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-2026-22245/ (Markdown: https://insights.sbomify.com/CVE-2026-22245/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-22245
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-22245
- OSV: https://osv.dev/vulnerability/CVE-2026-22245

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-22245/
Summaries are generated and may contain mistakes; the official description above is the record.