SEPTEMBER 9, 2026
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Case File

CVE-2026-55407

MEDIUM · CVSS 6.3 EPSS 0.42% Public Exploit

Source: NVD + CISA KEV + EPSS · Published 2026-07-16 · Last synced 2026-08-15

CyberRota Analysis

AI-Generated

The decode_unknown_field function in Buffa's protobuf decoder is vulnerable to memory exhaustion attacks due to unregulated heap memory allocation based on untrusted input. An attacker can exploit this vulnerability to crash a process by sending specially crafted protobuf messages, potentially amplifying memory usage by up to 22 times. Organizations using Buffa versions prior to 0.8.0, particularly those handling untrusted protobuf data, should prioritize upgrading to mitigate this risk.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2026-55407
Severity
MEDIUM
CVSS
6.3
EPSS
0.42%

Original NVD Description

Buffa is a pure-Rust Protocol Buffers implementation with first-class protobuf editions support. Prior to 0.8.0, the decode_unknown_field function in buffa's protobuf decoder allocated heap memory in proportion to untrusted input (unknown fields in the serialized protobuf) without enforcing an allocation budget, affecting any message decoded from untrusted input using code generated with preserve_unknown_fields=true (the default); a small, well-formed payload of nested unknown fields inside a StartGroup could trigger roughly 22x memory amplification (for example a 64 MiB input forcing about 1.4 GB of heap allocation), and length-delimited unknown fields could be sized arbitrarily, so an unauthenticated attacker could crash a process through memory exhaustion because the top-level message size cap did not account for in-decode amplification. This issue is fixed in version 0.8.0.