Medium severity · published Oct 27, 2026
CVE-2026-109088
libXtst RECORD EnableContext Reply Endless Loop
New
6.5
CVSS
–
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?
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
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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