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CVE-2026-59845

MEDIUM 5.3

Published 2026-07-21 · Last modified 2026-08-17

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.

NO EXPLOITATION SIGNALS

No known exploitation, public exploit, or elevated probability at this time. Track for changes.

Exploitation likelihood

0.1%chance of exploitation in 30 days · 1st percentile

○ In CISA KEV ○ Public exploit / PoC

Impact if exploited

5.3CVSS 3.1 · MEDIUM

  • ConfidentialityNone
  • IntegrityNone
  • AvailabilityHigh

What an attacker needs

  • Access: Requires local access to the host
  • Privileges: Requires a low-privilege account
  • User interaction: A user must take an action (click / open a file)
  • Complexity: Needs a race window or specific setup

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept & exploit code

Test against your own equipment

curl -s https://vulnpedia.com/cve/CVE-2026-59845/poc.jsonMachine-readable PoC index for this CVE (for automation).

Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-59845/poc.json

Affected

Vendors Red Hat Libssh Redhat

Products Red Hat Enterprise Linux 10 Red Hat Hardened Images Red Hat Enterprise Linux 8 Red Hat Enterprise Linux 9 Libssh Hardened Images Enterprise Linux

Weakness (CWE)

  • CWE-390: Detection of Error Condition Without Action

CVSS vector

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

Known Affected Software Configurations

VendorProductVersion range
LibsshLibssh*
RedhatHardened Images*
RedhatEnterprise Linux8.0
RedhatEnterprise Linux9.0
RedhatEnterprise Linux10.0

All CVSS metrics

  • MEDIUM 5.3 v3.1 · CNA Primary
    CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:N/I:N/A:H
  • MEDIUM 5.3 v3.1 · NVD Secondary
    CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:N/I:N/A:H
  • MEDIUM 5.9 v3.1 · NVD Primary
    CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:N/I:N/A:H

References

Advisories

Sources: NVD · CVE.org · EPSS