# CVE-2026-55874: SeaweedFS: Path traversal in the S3 gateway X-Amz-Copy-Source header allows cross-bucket object read

> An authenticated user can read objects from other buckets via path traversal in the S3 gateway copy header.

- **Severity:** High 7.7 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A: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 Jul 2026
- **Updated:** 8 Jul 2026
- **Also known as:** BIT-seaweedfs-2026-55874, GHSA-56wq-x3wv-3ff4, GO-2026-6327, MINI-c2vg-2542-rmw4, MINI-fmmc-x39j-p2cq

## What is CVE-2026-55874?

CVE-2026-55874 is a high-severity path traversal vulnerability in seaweedfs, published on 8 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

SeaweedFS is a distributed storage system. Prior to 4.34, the S3 API gateway does not reject dot-dot path segments in the X-Amz-Copy-Source header used by CopyObject and UploadPartCopy, allowing an authenticated identity scoped to one bucket to read objects from other buckets through server-side copy. This issue is fixed in version 4.34.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-55874?

4 open source packages ship an affected version, including github.com/seaweedfs/seaweedfs and seaweedfs.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/seaweedfs/seaweedfs` | Go | All versions | 0.0.0-20260612000715-b44cf51fe931 |
| `github.com/seaweedfs/seaweedfs` | Go | All versions | 0.0.0-20260612000715-b44cf51fe931 |
| `github.com/seaweedfs/seaweedfs` | Go | All versions | 0.0.0-20260612000715-b44cf51fe931 |
| `seaweedfs` | Bitnami | All versions | 4.34.0 |

## How do I fix CVE-2026-55874?

Upgrade github.com/seaweedfs/seaweedfs to 0.0.0-20260612000715-b44cf51fe931 or later.

## Is CVE-2026-55874 being exploited?

There is no known exploitation of CVE-2026-55874 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55874 and fix it if it is affected.

What it is: CVE-2026-55874 is a high-severity path traversal vulnerability in seaweedfs, published on 8 Jul 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-2026-55874 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/seaweedfs/seaweedfs (Go): affected all versions; fixed in 0.0.0-20260612000715-b44cf51fe931
- github.com/seaweedfs/seaweedfs (Go): affected all versions; fixed in 0.0.0-20260612000715-b44cf51fe931
- github.com/seaweedfs/seaweedfs (Go): affected all versions; fixed in 0.0.0-20260612000715-b44cf51fe931
- seaweedfs (Bitnami): affected all versions; fixed in 4.34.0

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-2026-55874/ (Markdown: https://insights.sbomify.com/CVE-2026-55874/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55874
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55874
- OSV: https://osv.dev/vulnerability/CVE-2026-55874

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-55874/
Summaries are generated and may contain mistakes; the official description above is the record.