{"id":"CVE-2026-54425","title":"Apache bRPC: Stack Exhaustion via Recursive HPACK Dynamic Table Size Update Decoding","summary":"Uncontrolled recursion in the HTTP/2 HPACK decoder in Apache bRPC before 1.18.0 allows remote attackers to cause denial of service by sending a crafted HTTP/2 header block containing many consecutive Dynamic Table Size Update entries. Ea…","severity":"none","cwe":["CWE-674"],"vendor":"Apache Software Foundation","product":"apache/brpc","affected":["apache/brpc < 1.18.0"],"published":"2026-10-21","updated":"2026-10-21","sourceUpdated":"2026-10-21T11:31:19.989Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-54425","references":[{"url":"https://lists.apache.org/thread/2pf15ojj0vr7rtx95677kgtl1mx3gdgb"}],"tags":["cve.org"],"ingestedAt":"2026-10-21T11:47:58.157Z","slug":"CVE-2026-54425","body":"## Overview\n\nUncontrolled recursion in the HTTP/2 HPACK decoder in Apache bRPC before 1.18.0 allows remote attackers to cause denial of service by sending a crafted HTTP/2 header block containing many consecutive Dynamic Table Size Update entries. Each update was decoded by recursively invoking the HPACK decoder, which could exhaust the thread stack before a header field or end of input was reached.\n\nRoot Cause:\nThe bRPC HPACK decoder recursively decoded the next entry after processing a Dynamic Table Size Update. The decoder did not bound the recursion depth, so a long sequence of update entries could consume excessive stack space.\n\nAffected Scenarios:\nUse bRPC with the built-in HTTP/2 implementation to accept HTTP/2 traffic from an untrusted network.\n\nHow to Fix:\n1. Upgrade bRPC to version 1.18.0, which fixes this issue.\n2. Apply this patch:  https://github.com/apache/brpc/pull/3343 \n\nNote:\nThe fix changes HPACK Dynamic Table Size Update decoding to use iterative parsing instead of recursive parsing.\n\n## Affected\n\n- `apache/brpc < 1.18.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}