{"id":"CVE-2026-54425","aliases":["EUVD-2026-107169","GHSA-95vv-8ch6-6f8f"],"status":"published","title":"Apache bRPC: Stack Exhaustion via Recursive HPACK Dynamic Table Size Update Decoding","description":"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. 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.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"adp","from":"cve"},"epss":{"day":"2026-11-12","score":0.0065,"percentile":0.51659,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-674"],"published":"2026-10-21T11:31:19Z","modified":"2026-10-30T15:35:17Z","products":[{"vendor":"apache software foundation","product":"apache brpc"}],"references":[{"url":"https://lists.apache.org/thread/2pf15ojj0vr7rtx95677kgtl1mx3gdgb","tags":["vendor-advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-54425"},{"url":"https://github.com/advisories/GHSA-95vv-8ch6-6f8f"}],"sources":{"cve":[{"id":"CVE-2026-54425","title":"Apache bRPC: Stack Exhaustion via Recursive HPACK Dynamic Table Size Update Decoding","description":"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. 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.","status":"published","published":"2026-10-21T11:31:19.989Z","modified":"2026-10-30T13:45:53.356Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"adp"}],"cwes":["CWE-674"],"updated_at":"2026-11-02T13:37:58.613221Z"}],"euvd":[{"id":"EUVD-2026-107169","description":"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. 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.","status":"published","published":"2026-10-21T11:31:19Z","modified":"2026-10-30T13:45:53Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T16:59:06.607412Z"}],"ghsa":[{"id":"GHSA-95vv-8ch6-6f8f","title":"Uncontrolled recursion in the HTTP/2 HPACK decoder in Apache bRPC before 1.18.0 allows remote...","description":"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. 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.","status":"published","published":"2026-10-21T12:31:08Z","modified":"2026-10-30T15:35:17Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-674"],"updated_at":"2026-11-02T15:14:50.819798Z"}],"nvd":[{"id":"CVE-2026-54425","description":"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. 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.","status":"published","published":"2026-10-21T12:17:21.053Z","modified":"2026-10-30T14:17:05.96Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-674"],"updated_at":"2026-11-02T14:13:02.045979Z"}]}}