Summary
SeaweedFS: Improper authorization in the S3Tables / Iceberg REST management API lets a low-privileged S3 user enumerate administrator-owned table buckets
SeaweedFS routes requests signed with SigV4 service s3tables to the S3Tables
management API. Authorization on that path collapsed account-less S3 identities
into the shared admin account and failed open, so a user holding only ordinary
S3 Read credentials, and no S3Tables-specific permission, could invoke
S3Tables management operations such as GET /buckets and enumerate
administrator-owned table bucket inventory (names and ARNs). The same handler
backs the Iceberg REST catalog, which was affected by the same flaw.
Affected versions
SeaweedFS >= 4.08, < 4.34 (the S3Tables management API was introduced in 4.08).
Patched versions
Fixed in 4.34 (#9961). Administrator status is now decided by theACTION_ADMIN capability rather than by a collapsed admin account id, S3Tables
authorization no longer defaults to allow, and the tautological ListTableBuckets
gate was removed. Related hardening of the same root cause landed in #9962,
#9963, and #9971.
Workaround
No configuration workaround, upgrade to 4.34 or later.
Credit
Reported by TA-MU-TA.
Impact
An authenticated low-privileged S3 user can cross the boundary between ordinary
S3 object access and S3Tables management. Confirmed impact is disclosure of
administrator-owned table bucket inventory (bucket names and ARNs); in shared or
multi-tenant deployments this can reveal tenant naming and operational structure.
The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions. Typical impact: unauthorized data access or execution of privileged operations.
CVE-2026-55873 has a CVSS score of 4.3 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.0.0-20260614205536-b13463880c1f); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-55873? CVE-2026-55873 is a medium-severity incorrect authorization vulnerability in github.com/seaweedfs/seaweedfs (go), affecting versions >= 0.0.0-20260128085517-09bb90e8dc16, < 0.0.0-20260614205536-b13463880c1f. It is fixed in 0.0.0-20260614205536-b13463880c1f. The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions.
- How severe is CVE-2026-55873? CVE-2026-55873 has a CVSS score of 4.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of github.com/seaweedfs/seaweedfs are affected by CVE-2026-55873? github.com/seaweedfs/seaweedfs (go) versions >= 0.0.0-20260128085517-09bb90e8dc16, < 0.0.0-20260614205536-b13463880c1f is affected.
- Is there a fix for CVE-2026-55873? Yes. CVE-2026-55873 is fixed in 0.0.0-20260614205536-b13463880c1f. Upgrade to this version or later.
- Is CVE-2026-55873 exploitable, and should I be worried? Whether CVE-2026-55873 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-55873 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-55873? Upgrade
github.com/seaweedfs/seaweedfsto 0.0.0-20260614205536-b13463880c1f or later.