Invoking client can cause server deadlock on unexpected responses in golang.org/x/crypto/ssh
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.
02 / AFFECTED SOFTWARE
Affected packages
51 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
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.
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.
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.
05 / REFERENCES
Further evidence
- https://go.dev/cl/781640
- https://go.dev/cl/781664
- https://go.dev/issue/79564
- https://groups.google.com/g/golang-announce/c/a082jnz-LvI
- https://access.redhat.com/errata/RHSA-2026:29455
- https://access.redhat.com/errata/RHSA-2026:35833
- https://access.redhat.com/errata/RHSA-2026:36199
- https://access.redhat.com/errata/RHSA-2026:36207
- https://access.redhat.com/errata/RHSA-2026:36319
- https://access.redhat.com/errata/RHSA-2026:36625
- https://access.redhat.com/errata/RHSA-2026:36648
- https://access.redhat.com/errata/RHSA-2026:36651
- https://access.redhat.com/errata/RHSA-2026:36796
- https://access.redhat.com/errata/RHSA-2026:36797
- https://access.redhat.com/errata/RHSA-2026:36808
- https://access.redhat.com/errata/RHSA-2026:37072
- https://access.redhat.com/errata/RHSA-2026:37268
- https://access.redhat.com/errata/RHSA-2026:37271
- https://access.redhat.com/errata/RHSA-2026:37272
- https://access.redhat.com/errata/RHSA-2026:37275
- https://access.redhat.com/errata/RHSA-2026:37278
- https://access.redhat.com/errata/RHSA-2026:37286
- https://access.redhat.com/errata/RHSA-2026:37296
- https://access.redhat.com/errata/RHSA-2026:37387
- https://access.redhat.com/errata/RHSA-2026:40118
- https://access.redhat.com/errata/RHSA-2026:40262
- https://access.redhat.com/errata/RHSA-2026:40945
- https://access.redhat.com/errata/RHSA-2026:40969
- https://access.redhat.com/errata/RHSA-2026:40972
- https://access.redhat.com/errata/RHSA-2026:40974
- https://access.redhat.com/errata/RHSA-2026:41019
- https://access.redhat.com/errata/RHSA-2026:41031
- https://access.redhat.com/errata/RHSA-2026:41036
- https://access.redhat.com/errata/RHSA-2026:41066
- https://access.redhat.com/errata/RHSA-2026:42146
- https://access.redhat.com/errata/RHSA-2026:42796
- https://access.redhat.com/errata/RHSA-2026:43052
- https://access.redhat.com/errata/RHSA-2026:43692
- https://access.redhat.com/errata/RHSA-2026:46885
- https://access.redhat.com/errata/RHSA-2026:47735
- https://access.redhat.com/errata/RHSA-2026:48151
- https://access.redhat.com/errata/RHSA-2026:49944
- https://access.redhat.com/errata/RHSA-2026:51033
- https://access.redhat.com/errata/RHSA-2026:52857
- https://access.redhat.com/errata/RHSA-2026:52910
- https://access.redhat.com/errata/RHSA-2026:54400
- https://access.redhat.com/errata/RHSA-2026:54531
- https://access.redhat.com/security/cve/CVE-2026-39830
- https://bugzilla.redhat.com/show_bug.cgi?id=2480684
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39830.json
- https://nvd.nist.gov/vuln/detail/CVE-2026-39830
- https://pkg.go.dev
- https://pkg.go.dev/vuln/GO-2026-5017
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39830.json
- https://access.redhat.com/errata/RHSA-2026:57194
- https://cs.opensource.google/go/x/crypto