Buffer overflow in Golang Crypto
CVE-2026-39830
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.
EPSS exploit prediction
EPSS: 0.006 (48.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 48.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
Weakness classification (CWE)
References
- go.dev/issue/79564 (Issue Tracking)
- groups.google.com/g/golang-announce/c/a082jnz-LvI (Mailing List)
- go.dev/cl/781640 (Issue Tracking)
- go.dev/cl/781664 (Issue Tracking)
- pkg.go.dev/vuln/GO-2026-5017 (Vendor Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-39830?
- CVE-2026-39830 is a critical-severity vulnerability in Golang Crypto, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 9.1/10. Published 2026-05-22.
- How severe is CVE-2026-39830?
- Critical severity. CVSS v3 base score is 9.1 out of 10.