CVE-2026-59843: libssh · Uncontrolled Resource Consumption
Affects libsshSource GCVE Database
Not known to be exploited · CVSS 6.5 Medium.
Data as of 30 Oct 2026, 06:59 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 46% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 21 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Red Hatredhat/libsshpkg:rpm/redhat/libsshOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
No workaround or mitigation is currently available. Users should monitor Red Hat advisories for updates and apply any future patches once released.
Description
A vulnerability in libssh allows a remote authenticated peer to advertise a zero maximum packet size in SSH_MSG_CHANNEL_OPEN, causing subsequent channel writes to enter an infinite loop that consumes CPU resources and leads to denial of service.
References
- nvd.nist.gov/vuln/detail/CVE-2026-59843 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:42922 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-59843 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2498176 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:55855 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:62217 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:62218 (opens in a new tab)