Medium severity · published Oct 27, 2026
CVE-2026-109088
libXtst RECORD EnableContext Reply Endless Loop
New
6.5
CVSS
0.3%
EPSS
No
On KEV
Description
A malicious X server could send malformed RECORD EnableContext reolies that can cause a X client using the parse_reply_call_callback function in libXtst before 1.2.6 to enter a endless loop.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 20% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
libXtst · X.org
before 1.2.6 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-109088
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-109088
gitlab.freedesktop.org
https://gitlab.freedesktop.org/xorg/lib/libxtst/-/merge_requests/11
More from libXtst
7.5
CVE-2016-7952
X.org libXtst before 1.2.3 allows remote X servers to cause a denial of service (infinite loop) via a reply in the (1) XRecordStartOfData, (2) XRecordEndOfData, or (3)…
7.1
CVE-2026-94286
Out-of-bounds read in libXtst's RECORD reply parser