CVE-2026-33811: Go standard library net · Double Free
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
- 0.8% chance of exploitation in 30 days – higher than 58% 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
A fix is available via configuration change: applications should be configured to use the pure Go DNS resolver instead of the cgo DNS resolver by setting the environment variable GODEBUG=netdns=go. This mitigation requires restarting affected applications or services. Users should verify that this change does not negatively affect DNS resolution in their environment.
Description
When using LookupCNAME with the cgo DNS resolver, a very long CNAME response can trigger a double-free of C memory and a crash.
References
- go.dev/issue/78803 (opens in a new tab)
- go.dev/cl/767860 (opens in a new tab)
- groups.google.com/g/golang-announce/c/qcCIEXso47M (opens in a new tab)
- pkg.go.dev/vuln/GO-2026-4981 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-33811 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2467822 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33811.json (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:42079 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:41019 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:42078 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:42082 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:48151 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36796 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:39810 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:42150 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:42151 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:42240 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:39272 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:35832 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:34357 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:42946 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:39573 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:38504 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:39266 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36776 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:39319 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36617 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:34359 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:47952 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:34364 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:41030 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:44622 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:47149 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:43692 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36319 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36625 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36207 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:42132 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:33574 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36651 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:40945 (opens in a new tab)
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- access.redhat.com/errata/RHSA-2026:23262 (opens in a new tab)
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- access.redhat.com/errata/RHSA-2026:41928 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:43038 (opens in a new tab)
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- access.redhat.com/errata/RHSA-2026:36648 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:35994 (opens in a new tab)
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- access.redhat.com/errata/RHSA-2026:35995 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:33120 (opens in a new tab)
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- access.redhat.com/errata/RHSA-2026:42852 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:46885 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:41055 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:47735 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:49703 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:50319 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:50336 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:50300 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:50205 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:50843 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:51033 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:51057 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:51187 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:51341 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:51194 (opens in a new tab)
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- access.redhat.com/errata/RHSA-2026:57194 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:49702 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:22120 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:22112 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:57649 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:49712 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:22121 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:59467 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:56790 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:56789 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:59559 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:56785 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:56910 (opens in a new tab)
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- access.redhat.com/errata/RHSA-2026:56912 (opens in a new tab)
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- access.redhat.com/errata/RHSA-2026:57488 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:60302 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:60520 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:61313 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:61253 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:60025 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:60018 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:65534 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:65886 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:65126 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:66022 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:67149 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:67319 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:67287 (opens in a new tab)