CVE-2026-39834

critical · 9.1

When writing data larger than 4GB in a single Write call on an SSH channel, an integer overflow in the internal payload size calculation caused the write loop to spin indefinitely, sending empty packets without making progress. The size comparison now uses int64 to prevent truncation.

9.1

CVSS

0.5%

EPSS (exploit prob.)

43rd

EPSS percentile

2026-05-22

Published

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

Weaknesses

CWE-190

Affected products

Vendor	Product	Affected versions
golang	crypto	< 0.52.0

Check a specific version with /api/v1/cve/match.

References

https://go.dev/cl/781663
https://go.dev/issue/79567
https://groups.google.com/g/golang-announce/c/a082jnz-LvI
https://pkg.go.dev/vuln/GO-2026-5020

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-39834