CVE-2026-39830: golang.org/x/crypto/ssh · Deadlock
Affects golang.org/x/crypto/sshSource CVE Database V5
Not known to be exploited · CVSS 9.1 Critical : upgrade to 0.52.0 as a priority.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 52% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 0.52.0
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 22 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 golang.org/x/crypto/ssh to 0.52.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| golang.org/x/cryptogolang.org/x/crypto/ssh | Affected
| Fixed in
|
Gogolang.org/x/crypto/sshpkg:golang/golang.org/x/crypto/sshOther threats | Affected
| Fixed in– |
Gogolang.org/x/crypto/sshpkg:golang/golang.org/x/crypto/sshOther 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
The vendor advisory recommends restricting network access to any service utilizing the golang.org/x/crypto/ssh library exposed to untrusted networks. Implement firewall rules to allow connections only from trusted hosts or networks. Restarting the affected service may be necessary for the new network rules to take effect.
Description
A malicious SSH peer could send unsolicited global request responses to fill an internal buffer, blocking the connection's read loop. The blocked goroutine could not be released by calling Close(), resulting in a resource leak per connection. Unsolicited global responses are now discarded.
References
- go.dev/issue/79564 (opens in a new tab)
- groups.google.com/g/golang-announce/c/a082jnz-LvI (opens in a new tab)
- go.dev/cl/781640 (opens in a new tab)
- go.dev/cl/781664 (opens in a new tab)
- pkg.go.dev/vuln/GO-2026-5017 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-39830 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2480684 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39830.json (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:41019 (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-2026:36199 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:37072 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:35833 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:29455 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36808 (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-2026:36651 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:40945 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:40118 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:37275 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36648 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:41036 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:37387 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:42146 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:43052 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:42796 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:41066 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:41031 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:40262 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:40972 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:40974 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:40969 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36797 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:37271 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:37268 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:37272 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:37278 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:37286 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:37296 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:46885 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:47735 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:49944 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:51033 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:52857 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:52910 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:54400 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:54531 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:57194 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:59467 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:57801 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:60520 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:61314 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:65964 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:66521 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:66022 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:67450 (opens in a new tab)