CVE-2026-113431: ninenines cowlib · Unthrottled Resource Allocation
Affects ninenines cowlibSource CVE Database V5
Not known to be exploited · CVSS 8.7 High : upgrade to a3b15e29b3067644bfd580246c87f7af7a90b3b8 soon.
Data as of 6 Nov 2026, 11:04 UTC
Thin evidence
One scorer or none| CNA (EEF) | CVSS 4.0 | 8.7 |
|---|
- Patch
- Available – fixed in a3b15e29b3067644bfd580246c87f7af7a90b3b8
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 6 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Upgrade ninenines cowlib to a3b15e29b3067644bfd580246c87f7af7a90b3b8.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| nineninescowlib | Affected
| Fixed in– |
| cowlibninenines/cowlib | Affected
| Fixed in
|
Hexcowlibpkg:hex/cowlibOther threats | Affected
| Fixed in– |
CPE configurations (1)
cpe:2.3:a:ninenines:cowlib:*:*:*:*:*:*:*:*
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix for this vulnerability is available in cowlib as identified by commit a3b15e29b3067644bfd580246c87f7af7a90b3b8. Users should upgrade to the fixed version to mitigate the issue. No other vendor advisory indicates alternative mitigations or that no action is required.
Description
CVE-2026-113431 is a high-severity vulnerability in the ninenines cowlib HTTP/2 implementation that allows an unauthenticated remote attacker to exhaust server memory by exploiting the handling of HPACK-indexed header fields. The vulnerability arises because the decoding process does not properly limit the size of the decoded header list, allowing a small compressed input to expand into a very large memory allocation. This can lead to resource exhaustion across multiple streams and connections. The issue affects cowlib versions 2.7.0 and later and has been fixed in a commit identified by hash a3b15e29b3067644bfd580246c87f7af7a90b3b8.
References
- cna.erlef.org/cves/CVE-2026-113431.html (opens in a new tab)
- osv.dev/vulnerability/EEF-CVE-2026-113431 (opens in a new tab)
- github.com/ninenines/cowlib/commit/b461b119e78e4e09bb28b186b09da7ed4a86a0dd (opens in a new tab)
- github.com/ninenines/cowlib/commit/a3b15e29b3067644bfd580246c87f7af7a90b3b8 (opens in a new tab)