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.
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.
Published:
2026-10-21
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
Analysis
No analysis available yet.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Apache Software Foundation | Apache bRPC | unaffected |
|
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No data available yet.
Remediation
No remediation available yet.
Tracking
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Advisories
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References
History
Wed, 21 Oct 2026 11:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | Apache bRPC: Stack Exhaustion via Recursive HPACK Dynamic Table Size Update Decoding | |
| Weaknesses | CWE-674 | |
| References |
|
Subscriptions
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MITRE
Status: PUBLISHED
Assigner: apache
Published:
Updated: 2026-10-21T11:31:19.989Z
Reserved: 2026-06-14T06:18:42.168Z
Link: CVE-2026-54425
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-10-21T12:17:21.053
Modified: 2026-10-21T12:17:21.053
Link: CVE-2026-54425
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
-
CWE-674
Uncontrolled Recursion