CVE-2026-55874 is a high-severity (CVSS 7.7) Path Traversal vulnerability in github.com/seaweedfs/seaweedfs. O3 Security confirms whether CVE-2026-55874 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
SeaweedFS: Path traversal in the S3 gateway X-Amz-Copy-Source header allows cross-bucket object read
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-55874.
Real-World Exposure
github.com/seaweedfs/seaweedfsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/seaweedfs/seaweedfs | all versions | 0.0.0-20260612000715-b44cf51fe931 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/seaweedfs/seaweedfs. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/seaweedfs/seaweedfs to 0.0.0-20260612000715-b44cf51fe931 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-55874 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-55874 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-55874. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-55874 in your dependencies?
O3 detects CVE-2026-55874 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.