# CVE-2026-22187: Bio-Formats <= 8.3.0 Memoizer Unsafe Deserialization via .bfmemo Cache Files

> Attackers can trigger unsafe Java deserialization via crafted cache files, potentially leading to remote code execution or denial of service.

- **Severity:** Medium 6.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 7 Jan 2026
- **Updated:** 8 Oct 2026
- **Also known as:** GHSA-qjm3-cvp9-3jj3

## What is CVE-2026-22187?

CVE-2026-22187 is a medium-severity unsafe deserialization vulnerability in Open Microscopy Environment Bio-Formats, published on 7 Jan 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

Bio-Formats versions up to and including 8.3.0 perform unsafe Java deserialization of attacker-controlled memoization cache files (.bfmemo) during image processing. The loci.formats.Memoizer class automatically loads and deserializes memo files associated with images without validation, integrity checks, or trust enforcement. An attacker who can supply a crafted .bfmemo file alongside an image can trigger deserialization of untrusted data, which may result in denial of service, logic manipulation, or potentially remote code execution in environments where suitable gadget chains are present on the classpath.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2026-22187?

2 open source packages ship an affected version, including ome:pom-bio-formats. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `ome:pom-bio-formats` | Maven | All versions to 8.3.0 | None |
| `ome:pom-bio-formats` | Maven | All versions to 8.3.0 | None |

Products: Openmicroscopy Bio-Formats.

## How do I fix CVE-2026-22187?

No fix has been published for CVE-2026-22187 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-22187 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-22187 exists.

Public exploit code:

- Bio-Formats ≤ 8.3.0 performs unsafe Java deserialization of attacker-controlled .bfmemo cache files during image processing; crafted .bfmemo can trigger deserialization of untrusted data (DoS/logic manipulation; potentially RCE if gadget chains exist). (github_poc): https://github.com/George0Papasotiriou/CVE-2026-22187-Bio-Formats-unsafe-Java-deserialization-via-.bfmemo

## Other vulnerabilities in Open Microscopy Environment Bio-Formats

- [CVE-2026-22186](https://insights.sbomify.com/CVE-2026-22186/): Bio-Formats <= 8.3.0 XXE in Leica XLEF Metadata Parser (medium 4.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-22187 and fix it if it is affected.

What it is: CVE-2026-22187 is a medium-severity unsafe deserialization vulnerability in Open Microscopy Environment Bio-Formats, published on 7 Jan 2026. It can only be exploited from the same machine or local network, 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-2026-22187 exists.

Affected packages and fixed versions:
- ome:pom-bio-formats (Maven): affected all versions up to 8.3.0; no fix listed
- ome:pom-bio-formats (Maven): affected all versions up to 8.3.0; 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-2026-22187/ (Markdown: https://insights.sbomify.com/CVE-2026-22187/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-22187
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-22187
- OSV: https://osv.dev/vulnerability/CVE-2026-22187

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-22187/
Summaries are generated and may contain mistakes; the official description above is the record.