CVE-2026-54425 Apache bRPC: Stack Exhaustion via Recursive HPACK Dynamic Table Size Update Decoding
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-54425?
CVE-2026-54425 is a vulnerability in Apache bRPC, published on 21 Oct 2026.
Official 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.
Weakness: CWE-674
Which versions are affected by CVE-2026-54425?
How do I fix CVE-2026-54425?
No fix has been published for CVE-2026-54425 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-54425 being exploited?
There is no known exploitation of CVE-2026-54425 in the wild and no public exploit code.
Sources
Also known as GHSA-95vv-8ch6-6f8f.