Out-of-bounds read in Apache bRPC URL and header lookup tables
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-125 and the CVSS impact.
Summary
Apache bRPC before 1.18.0 reads past the end of its URL and header lookup tables on platforms where plain char is unsigned, such as ARM64. Input bytes with the high bit set become indices beyond the tables, which is an out-of-bounds read (CWE-125). A remote, unauthenticated attacker can crash the server with a crafted request URI, causing denial of service.
Written with Claude Haiku 5.5 from the sources below · 2026-10-30
Description from the CNA
Out-of-bounds reads in URL parsing and case-insensitive header lookup in Apache bRPC before version 1.18.0 on platforms where plain char is unsigned, such as ARM64, allow remote attackers to cause a process crash and denial of service by sending crafted input containing bytes with the high bit set. Root Cause: Two 256-entry lookup tables are accessed through pointers biased by 128 so that valid indices are in the range -128 to 127. Input bytes are promoted from plain char to int without first normalizing them to the signed-char range. On affected platforms, bytes in the range 0x80 to 0xFF therefore become indices 128 to 255 and read up to 127 bytes beyond the end of the underlying tables. Affected Scenarios: A remotely accessible bRPC HTTP server on an affected platform can reach the vulnerable URL lookup through an unauthenticated request URI containing a high-bit byte. The case-insensitive lookup is also reachable when untrusted header names are processed through APIs such as the HTTP/2 HPACK path. HTTP/1 header names containing high-bit bytes are rejected by the HTTP/1 parser before reaching the vulnerable lookup. Builds where plain char is signed, which commonly include x86_64 builds, are not affected by this issue. How to Fix: Choose one of the following options: 1. Upgrade Apache bRPC to version 1.18.0 or later. 2. Apply the patch from https://github.com/apache/brpc/pull/3376 . The fix normalizes lookup-table indices to the signed-char range before accessing the biased tables.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Upgrade Apache bRPC to 1.18.0 or later, or apply the upstream patch from pull request 3376 in the apache/brpc repository.
Written with Claude Haiku 5.5 from the sources below · 2026-10-30
- Fix · CNA Apache bRPC (Apache Software Foundation) Fixed in 1.18.0
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
Apache bRPC — lists.apache.org/thread/2pf15ojj0vr7rtx95677kgtl1mx3gdgb
35 records Highest priority Priority MEDIUM 18 MEDIUM, 17 LOW
Other records, highest priority first
- TI-2026-78552 Out-of-bounds write in Apache bRPC Redis command parserPriority MEDIUM 49
- TI-2026-78757 Authentication bypass in Apache bRPC servers using internal_portPriority MEDIUM 48
- TI-2026-78742 Missing authentication in Apache bRPC streaming RPC framesPriority MEDIUM 48
Timeline
- 2026-10-21 Threatist record created from CVE-2026-61916
- 2026-10-21 Alias added: GHSA-7g7p-w25v-9p63
- 2026-10-30 CVSS score added · CISA ADP
- 2026-10-30 CISA SSVC decision points changed
- 2026-11-01 Priority changed: LOW → MEDIUM
References
More Apache vulnerabilities
- TI-2025-18529 Apache Tomcat: Potential RCE and/or information disclosure and/or information corruption with partial PUT KEVCVSS 3.1CRITICAL 10.0
- TI-2024-30292 Apache OFBiz: Confused controller-view authorization logic (forced browsing) KEVCVSS 3.1CRITICAL 9.8
- TI-2024-26062 Apache OFBiz: Unauthenticated endpoint could allow execution of screen rendering code KEVCVSS 3.1CRITICAL 9.8
- TI-2024-21190 Apache OFBiz: Path traversal leading to RCE KEVCVSS 3.1CRITICAL 9.8
- TI-2024-18186 Apache HugeGraph-Server: Command execution in gremlin KEVCVSS 3.1CRITICAL 9.8
- TI-2023-25106 Deserialization of untrusted data in Apache ActiveMQ KEVCVSS 3.1CRITICAL 10.0
Sources
- CVE-2026-61916 · CVE Program
- CVE-2026-61916 · NVD
- FIRST EPSS
- GHSA-7g7p-w25v-9p63 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences