{"cve":"CVE-2026-55407","nvd":{"published":"2026-07-16T17:16:57.770","modified":"2026-10-24T20:10:00.137","status":"Deferred","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.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","score":6.3},"cvss_v3":null,"cwes":["CWE-400","CWE-770","CWE-789"],"references":["https://github.com/anthropics/buffa/commit/278fa43fcff661d4ee6bd83b75955a153d4281fc","https://github.com/anthropics/buffa/pull/184","https://github.com/anthropics/buffa/releases/tag/v0.8.0","https://github.com/anthropics/buffa/security/advisories/GHSA-f9qc-qg88-7pq5"],"products":[],"source":"nvd","synced_at":"2026-10-25T17:50:08.599881581+00:00"},"epss":{"cve":"CVE-2026-55407","score":0.00755,"percentile":0.54842,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-f9qc-qg88-7pq5","url":"https://osv.dev/vulnerability/GHSA-f9qc-qg88-7pq5","summary":"Buffa Vulnerable to Memory Exhaustion Denial of Service in decode_unknown_field via Unbounded Allocation","modified":"2026-08-28T18:45:06.833393744Z","packages":[{"ecosystem":"crates.io","name":"buffa","purl":"pkg:cargo/buffa","ranges":["<0.8.0"],"fixed":["0.8.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}