NULL pointer dereference in Golang Crypto
CVE-2026-39835
SSH servers which use CertChecker as a public key callback without setting IsUserAuthority or IsHostAuthority could be caused to panic by a client presenting a certificate. CertChecker now returns an error instead of panicking when these callbacks are nil.
Vulnerability class: Improper Certificate Validation
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.005 (41.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 41.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
Weakness classification (CWE)
References
- go.dev/issue/79563 (Issue Tracking)
- groups.google.com/g/golang-announce/c/a082jnz-LvI (Mailing List)
- go.dev/cl/781660 (Issue Tracking)
- pkg.go.dev/vuln/GO-2026-5015 (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
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-39835?
- CVE-2026-39835 is a medium-severity vulnerability in Golang Crypto, classified under Improper Certificate Validation. CVSS score: 5.3/10. Published 2026-05-22.
- How severe is CVE-2026-39835?
- Medium severity. CVSS v3 base score is 5.3 out of 10.