| id: GO-2026-5048 |
| modules: |
| - module: github.com/iskorotkov/avro/v2 |
| versions: |
| - fixed: 2.33.0 |
| vulnerable_at: 2.32.0 |
| packages: |
| - package: github.com/iskorotkov/avro/v2 |
| - module: github.com/hamba/avro/v2 |
| vulnerable_at: 2.31.0 |
| packages: |
| - package: github.com/hamba/avro/v2 |
| summary: Denial of service via unbounded map allocations in github.com/iskorotkov/avro/v2 and github.com/hamba/avro/v2 |
| description: |- |
| The Avro map decoder accepts attacker-controlled block-element counts from the |
| wire format and grows the destination map without enforcing an upper bound. A |
| producer can declare an arbitrarily large map (in one block, or chunked across |
| many sub-limit blocks) and exhaust process memory until the OOM killer fires. |
| |
| The fix introduces Config.MaxMapAllocSize with cumulative enforcement across |
| block boundaries. The new limit is opt-in: the field defaults to zero, which |
| preserves the previous unbounded behavior for backward compatibility. Upgrading |
| to v2.33.0 alone does not mitigate the issue; consumers of untrusted Avro data |
| must explicitly set MaxMapAllocSize on their avro.Config. |
| ghsas: |
| - GHSA-mx64-mj3q-7prj |
| credits: |
| - Ivan Korotkov |
| - Daniel Błażewicz |
| references: |
| - advisory: https://github.com/iskorotkov/avro/security/advisories/GHSA-mx64-mj3q-7prj |
| - fix: https://github.com/iskorotkov/avro/commit/5192df96a158999344ac96ebcb1f7461d626f6d7 |
| source: |
| id: GHSA-mx64-mj3q-7prj |
| created: 2026-07-21T19:47:07.548189-04:00 |
| review_status: REVIEWED |
