# CVE-2026-77611: Missing authorization in seaweedfs

> Authenticated users can bypass object-scope restrictions to overwrite unrelated files at the bucket root via PutObjectAcl.

- **Severity:** High 7.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L`)
- **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:** 26 Aug 2026
- **Updated:** 27 Aug 2026
- **Also known as:** BIT-seaweedfs-2026-77611, GHSA-9x53-cjpr-m682, MINI-rhv5-hf6x-q63x

## What is CVE-2026-77611?

CVE-2026-77611 is a high-severity missing authorization vulnerability in seaweedfs, published on 26 Aug 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 for files and blobs. In versions prior to 4.40, an authenticated S3 principal with permissions scoped to a nested object key can overwrite a different object outside that scope by calling PutObjectAcl on the key it is allowed to access. The handler authorizes the request against the requested nested key but then writes the updated entry back to the bucket root rather than the key's actual parent directory, so an ACL change on allowed/protected.txt is instead applied to protected.txt at the bucket root. Because the update carries the full entry rather than only ACL metadata, an existing target object is overwritten with the content, metadata, owner information, and ACL of the scoped object, bypassing the object-level action scoping configured through the static S3 identity file. This issue is fixed in version 4.40.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2026-77611?

1 open source package ship an affected version, including seaweedfs.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `seaweedfs` | Bitnami | All versions | 4.40.0 |

## How do I fix CVE-2026-77611?

Upgrade seaweedfs to 4.40.0 or later.

## Is CVE-2026-77611 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-77611 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-77611 and fix it if it is affected.

What it is: CVE-2026-77611 is a high-severity missing authorization vulnerability in seaweedfs, published on 26 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-77611 exists.

Affected packages and fixed versions:
- seaweedfs (Bitnami): affected all versions; fixed in 4.40.0

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-2026-77611/ (Markdown: https://insights.sbomify.com/CVE-2026-77611/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-77611
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-77611
- OSV: https://osv.dev/vulnerability/CVE-2026-77611

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-77611/
Summaries are generated and may contain mistakes; the official description above is the record.