CVE-2026-6409 Affecting protobuf package, versions *
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-UBUNTU2004-PROTOBUF-16100984
- published22 Apr 2026
- disclosed16 Apr 2026
Introduced: 16 Apr 2026
CVE-2026-6409 (opens in a new tab)How to fix?
There is no fixed version for Ubuntu:20.04 protobuf.
NVD Description
Note: Versions mentioned in the description apply only to the upstream protobuf package and not the protobuf package as distributed by Ubuntu.
See How to fix? for Ubuntu:20.04 relevant fixed versions and status.
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.