CVE-2026-54425

Apache bRPC: Stack Exhaustion via Recursive HPACK Dynamic Table Size Update Decoding

HIGH
7.5
CVSS Score
Published: October 21, 2026 at 11:31 AM UTC
Updated: October 30, 2026 at 02:17 PM UTC
1 product affected across 1 vendorBrpc

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Severity
HIGH7.5
Exploit prediction
EPSS 0.7%
SSVC
No known exploit

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. Root Cause: The 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. Affected Scenarios: Use bRPC with the built-in HTTP/2 implementation to accept HTTP/2 traffic from an untrusted network. How to Fix: 1. Upgrade bRPC to version 1.18.0, which fixes this issue. 2. Apply this patch: https://github.com/apache/brpc/pull/3343 Note: The fix changes HPACK Dynamic Table Size Update decoding to use iterative parsing instead of recursive parsing.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

All versions

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-674

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