Security research · CVE-2026-61916
Apache bRPC: Out-of-bounds Read in URL and Header Lookup Tables on Unsigned-char Platforms
Published Oct 21, 2026 · catalog updated Oct 21, 2026 · Apache Software Foundation Apache bRPC
Last checked Nov 3, 2026. A connected source was read within the last 7 days.
Check if you run it
No confirmed exploitation is on record for CVE-2026-61916. EPSS is 0.57%. Act only if a listed version of Apache Software Foundation Apache bRPC is installed.
Gaps on this record
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
Same product and reporting
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- Severity
- Unknown—
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.57%
- Remediation
- Not established
- Affected products
- vendor Apache Software Foundation Apache bRPC
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.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
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- vendor Apache Software Foundation Apache bRPCversion unspecified
How to fix CVE-2026-61916
No stored fix
No vendor fix text is stored. Use the linked advisory before you change production.
Version check
No version range is stored, so an installed version cannot be checked on this page.
Advisory
Open the cve_org record and follow its fix.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-61916. EPSS is 0.57%. Act only if a listed version of Apache Software Foundation Apache bRPC is installed.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-125: Out-of-bounds Read. EPSS 0.57%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Oct 21, 2026 · NIST NVD
Detected
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 in
Sources
- CVE.orgVulnerability recordCVE-2026-61916
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 wit
cve.org - FIRST EPSSExploitation probabilityCVE-2026-61916
30-day exploitation probability 0.57%
first.org - NIST NVDVulnerability recordCVE-2026-61916
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 wit
nvd.nist.gov
References
Freshness
Last verified in this catalog Nov 3, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.
- FIRST EPSSOct 31, 2026
- CVE.orgOct 21, 2026
- NIST NVDOct 21, 2026