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CVE-2026-6409

Denial of Service (DoS) vulnerability exists in the Protobuf PHP library during the parsing of untrusted input

Published: Apr 16, 2026Updated: Apr 17, 2026 Sources: CVE List NVD BDUCWE-20
7.5HIGH
NVD MITRE
EPSS Score
0.4%
Top 71.3%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
Not available

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LC:NI:NA:H
Exploitability
AV:NAccess Vector
Network
AC:LAccess Complexity
Low
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
H
Open in CVSS calculator →

Weaknesses

CWE-20

Affected Products

ООО «Ред Софт»
commercial·RUaka red soft
РЕД ОСOn-premOS
Operating Systems / linux-distro
Google Inc
commercial·USaka google
ProtobufLibraryLibrary
OSS Libraries / generic-library
Protocol Buffers
oss-projectaka protocolbuffers, protocol-buffer, google protocol buffers
Protobuf-php (Pecl)Library
OSS Libraries / generic-library

Exploitability

Official Patch Available
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique
Initial Access
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References

https://github.com/protocolbuffers/protobuf/issues/25067
github.com
https://github.com/protocolbuffers/protobuf/security/advisories/GHSA-p2gh-cfq4-4wjc
github.com
https://redos.red-soft.ru/support/secure/uyazvimosti-red-os-8-0/uyazvimost-protobuf-cve-2026-6409-8.0/?sphrase_id=1528323
redos.red-soft.ru
and 1 more references View all →

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