CVE-2026-39836: Go standard library net · Uncaught Exception
Affects Go standard library netSource CVE Database V5
Not known to be exploited · CVSS 7.5 High : upgrade to 1.26.3 or 1.25.10 soon.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 50% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.26.3, 1.25.10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 7 May 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 Go standard library net to 1.26.3 or 1.25.10.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Go standard librarynet | Affected
| Fixed in
|
| Go standard librarynet | Affected
| Fixed in
|
Gonetpkg:golang/netOther threats | Affected
| Fixed in– |
Gonetpkg:golang/netOther threats | Affected
| Fixed in
|
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 input validation or sanitization to prevent NUL characters from reaching the Dial and LookupPort functions in the Go net package on Windows platforms.
Description
CVE-2026-39836 is a high-severity vulnerability in the Go standard library's net package on Windows platforms. The Dial and LookupPort functions panic when given input containing a NUL (0) character, causing an uncaught exception that can crash the application. This results in a denial of service condition. There is no impact on confidentiality or integrity reported.