CVE-2026-39834

Aliases:GO-2026-5020GHSA-rm3j-f69w-wqmq
Advisory lineage Upstream: 0 Downstream: 51
Analyzed
Published: 22 May 2026, 02:31
Last modified:22 May 2026, 18:50

Vulnerability Summary

Overall Risk (default)
high
70/100
CVSS Score
9.1 CRITICAL
v3.1 (cve.org)
EPSS Score
0.47% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

22 May 2026, 02:31
Published
Vulnerability first disclosed
22 May 2026, 18:50
Last Modified
Vulnerability information updated

Description

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.

CVSS Metrics

  • v3.1•CRITICAL•Score: 9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

EPSS Trends

Current EPSS score: 0.47%• Percentile: 37%

Techniques & Countermeasures

  • CWE-190•Integer Overflow or Wraparound

    The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

Affected Systems

  • golang•crypto

    < 0.52.0

  • golang.org/x•crypto

    < 0.52.0

  • golang.org/x/crypto•ssh

    < 0.52.0

  • golang.org/x/crypto•golang.org/x/crypto/ssh

    < 0.52.0

References (6)