CVE-2026-43973: ninenines gun · Unthrottled Resource Allocation
Affects ninenines gunSource CVE Database V5
Not known to be exploited · CVSS 8.7 High : upgrade to 2.4.0 soon.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 41% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 2.4.0, f3e7e0568b3c4cf9fa4bea79d5116e67ce76ad25
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 8 Jun 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 30 Oct 2026.
What to do
Upgrade gun and ninenines/gun to 2.4.0; gun to f3e7e0568b3c4cf9fa4bea79d5116e67ce76ad25.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| nineninesgun | Affected
| Fixed in
|
| nineninesgun | Affected
| Fixed in
|
Hexninenines/gunpkg:hex/ninenines/gunOther threats | Affected
| Fixed in
|
GitHubgunpkg:github/gunOther threats | Affected
| Fixed in
|
CPE configurations (1)
cpe:2.3:a:ninenines:gun:*:*:*:*:*:*:*:*
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
If you cannot patch yet, users should consider mitigating exposure by avoiding untrusted or malicious servers or implementing external controls to limit response sizes.
Description
CVE-2026-43973 is a high-severity vulnerability in the ninenines gun HTTP client library affecting versions 1.0.0 up to but not including 2.4.0. The issue is due to unbounded HTTP/1.1 response buffering in the gun_http:handle/5 function, which allows a malicious server to cause uncontrolled memory consumption by sending partial HTTP responses that never complete. This can lead to exhaustion of client memory and a node-wide crash.