High severity · published Sep 18, 2026
CVE-2026-91149
Cockpit: cockpit: denial of service via unbounded connection thread spawning
7.5
CVSS
0.3%
EPSS
No
On KEV
Description
A flaw was found in Cockpit. An unauthenticated remote attacker can exploit this vulnerability by initiating and sustaining numerous simultaneous connections to the `cockpit-tls` service. This forces the service to create an unbounded number of detached threads, consuming system resources such as memory and file descriptors. The primary consequence is a denial of service (DoS), leading to degradation or complete unavailability of the Cockpit service for legitimate users.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 28% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RH
Red Hat Enterprise Linux 10 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 7 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 8 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 9 · Red Hat
All versions, or not specified · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-91149
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-91149
vdb-entry
https://access.redhat.com/security/cve/CVE-2026-91149
issue-tracking
https://bugzilla.redhat.com/show_bug.cgi?id=2479422
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