CVE-2026-6409
unknown
CVSS v3
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CVSS v4 NEW
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VIR risk
—
Description
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.
Predictions
Exploit likelihood
20%
Patch ETA
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Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
Debian Affected 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Affected | — |
| sid | Affected | — |
| forky | Affected | — |
| bullseye | Affected | — |
| bookworm | Affected | — |
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| Packagist | google/protobuf | <4.33.6 | 4.33.6 |
References
- https://github.com/protocolbuffers/protobuf/security/advisories/GHSA-p2gh-cfq4-4wjc
- https://nvd.nist.gov/vuln/detail/CVE-2026-6409
- 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://github.com/protocolbuffers/protobuf
- https://security-tracker.debian.org/tracker/CVE-2026-6409
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.