GHSA-6v7p-g79w-8964
MessagePack for Python: Out-of-bounds read / crash on Unpacker reuse after a caught error
At a glance
- Published
- Updated
- CVE
- CVE-2026-57585
- Aliases
- PYSEC-2026-3625
- CVSS_V3
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Description
### Impact If the Unpacker is used repeatedly after an error occurs, the process may crash with a SEGV. If the Unpacker is used repeatedly to unpack untrusted input from external sources, it may be vulnerable to a DoS attack. ### Patches v1.2.1 ### Workarounds Users should create a new Unpacker instead of reusing the same Unpacker after an error occurs. Applying the above patch can prevent SEGV, but reusing the Streaming Unpacker after it has encountered an error will not yield correct data. If an error occurs during Streaming Unpacking, the Stream and Streaming Unpacker should be discarded. Therefore, this is not just a workaround but the correct solution. The above patch only prevents crashes from incorrect usage.
Affected packages
| Package | Versions |
|---|---|
| PyPI · msgpack | introduced 0, fixed 1.2.1 |
References
- https://github.com/msgpack/msgpack-python/security/advisories/GHSA-6v7p-g79w-8964 WEB
- https://github.com/msgpack/msgpack-python/commit/2c56ddb5d0025ed481d962c0f5d62d19dec7476d WEB
- https://github.com/msgpack/msgpack-python PACKAGE
- https://github.com/msgpack/msgpack-python/releases/tag/v1.2.1 WEB
Sources
| Source | Licence |
|---|---|
| OSV.dev | CC-BY 4.0 — GitHub Advisory Database |