SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2026-39830

A malicious SSH peer could send unsolicited global request responses to fill an internal buffer, blocking the connection's read loop.

CRITICAL 9.1EPSS 0.62%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.62%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
9.1 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
EPSS
0.62% probability · 48th percentile
CISA KEV
Not listed
Weakness
CWE-119, CWE-772
Affected
golang/crypto
Source
security@golang.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.