Auth bypass in Seaweedfs

CVE-2026-72921

SeaweedFS is a distributed storage system. Prior to 4.24, the weed/server/filer_server_handlers.go allowed_prefixes authorization check used strings.HasPrefix on raw path strings, so a filer JWT scoped to /tenant1 also authorized sibling paths such as /tenant1234, /tenant1-old, and /tenant1backup, enabling cross-tenant reads and writes with a valid scoped token. This issue is fixed in version 4.24.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.004 (34.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 34th percentile — 34.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-72921: held from 0.002 to 0.004.

EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-72921?
CVE-2026-72921 is a high-severity vulnerability in Seaweedfs, classified under Incorrect Authorization. CVSS score: 8.1/10. Published 2026-08-11.
How severe is CVE-2026-72921?
High severity. CVSS v3 base score is 8.1 out of 10.