Integer Underflow Vulnerability in Apache bRPC on Various Platforms
CVE-2026-74755

Currently unrated

Key Information:

Vendor

Apache
Status
Apache Brpc
Vendor
CVE Published:
21 October 2026

What is CVE-2026-74755?

An integer underflow vulnerability in the mcpack2pb component of Apache bRPC allows remote attackers to crash the server by sending a request with a zero value_size. This occurs as the UnparsedValue::as_string() function computes '_size - 1' without sufficient validation, leading to an underflow situation. When value_size is zero, the operation causes an overflow that results in an exception, which if uncaught, causes the server process to abort. Affected bRPC servers accepting specific protocol frames can be compromised with a single unauthenticated request. To safeguard against this vulnerability, users are advised to upgrade to bRPC version 1.18.0 or apply a provided patch.

Affected Version(s)

Apache bRPC 0 < 1.18.0

References

https://lists.apache.org/thread/2pf15ojj0vr7rtx95677kgtl1...
vendor-advisory

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Feng Zhijie (Independent security researcher)
.