CVE-2026-59845

Summary

A flaw was found in libssh. When ProxyCommand is used, an unchecked fork() failure can be stored as process ID -1; during cleanup, signals may then be sent across the caller's accessible process tree, leading to local denial of service.

Affected Software

VendorProductVersion RangeStatus
Red HatRed Hat Enterprise Linux 100:0.12.0-3.el10_2 < *unaffected
Red HatRed Hat Enterprise Linux 80:0.9.6-17.el8_10 < *unaffected
Red HatRed Hat Enterprise Linux 80:0.9.6-17.el8_10 < *unaffected
Red HatRed Hat Enterprise Linux 90:0.10.4-19.el9_8 < *unaffected
Red HatRed Hat Enterprise Linux 90:0.10.4-19.el9_8 < *unaffected
Red HatRed Hat Hardened Images0.12.1-4.hum1 < *unaffected

Weaknesses

  • CWE-390: Detection of Error Condition Without Action

Workarounds

To mitigate this issue, avoid using the ProxyCommand feature in libssh client configurations. This prevents the vulnerable code path from being exercised, thereby eliminating the risk of local denial of service due to unchecked fork() failures.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References