protocolbuffers/protobuf · Security
Protobuf: Denial of Service issue through malicious messages containing negative varints or deep recursion
- GHSA ID
- GHSA-p2gh-cfq4-4wjc
- CVE ID
- CVE-2026-6409
- Severity
- high
- Published
- Updated
- CVSS v4
- 7.1 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Description
Impact
A Denial of Service (DoS) vulnerability exists in the Protobuf PHP library during the parsing of untrusted input. Maliciously structured messages—specifically those containing negative varints or deep recursion—can be used to crash the application, impacting service availability.
Patches
Patches have been released to 5.34.0-RC1 and 4.33.6.
CWEs
- CWE-400 · Uncontrolled Resource Consumption
References
- https://github.com/protocolbuffers/protobuf/security/advisories/GHSA-p2gh-cfq4-4wjc ↗
- https://github.com/protocolbuffers/protobuf/issues/24159 ↗
- https://github.com/protocolbuffers/protobuf/issues/25067 ↗
- https://github.com/protocolbuffers/protobuf/commit/60e93d2d104f2af9cd345b1c6f3891d91430244a ↗
- https://github.com/protocolbuffers/protobuf/commit/c8e9b27d95c6ab2d0668b5889e7dac2c477b7038 ↗
- https://nvd.nist.gov/vuln/detail/CVE-2026-6409 ↗
- https://github.com/advisories/GHSA-p2gh-cfq4-4wjc ↗