VulnerabilityPublished 28 Sep 2026Updated 30 Sep 2026

CVE-2026-94285: x.org libX11 · Out-of-bounds Read

Affects x.org libX11Source CVE Database V5

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Not known to be exploited · CVSS 5.1 Medium : upgrade to 1.8.14 when convenient.

Data as of 12 Nov 2026, 23:25 UTC

CVSS 3.1 base score

5.1Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.8.14

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

Attack Vector: Local
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 28 Sep 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 13 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade libX11 and x.org/libx11 to 1.8.14.

Affected software

Product	Affected	Fixed in
x.orglibX11	Affected <1.8.14	Fixed in 1.8.14
X.orgx.org/libx11`pkg:deb/x.org/libx11`Other threats	Affected <1.8.14	Fixed in 1.8.14

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Users should monitor official x.org or libX11 advisories for updates and apply any available patches to versions before 1.8.14. Until a patch is confirmed, caution is advised when connecting to untrusted X servers.

Description

CVE-2026-94285 is an out-of-bounds read vulnerability in the byte-oriented codeset parser of libX11 versions before 1.8.14. This flaw could allow a malicious X server to crash connected X clients. The vulnerability has a medium severity rating with a CVSS score of 5.1. No known exploits are reported in the wild. Affected versions include all libX11 releases from 0 up to but not including 1.8.14.

Impact

The vulnerability allows a malicious X server to cause an out-of-bounds read in libX11 clients, potentially crashing them and causing denial of service. There is limited confidentiality impact but no integrity impact. No known exploitation in the wild has been reported.

Summary

An out-of-bounds read exists in libX11's byte-oriented codeset parser in versions prior to 1.8.14. This vulnerability could be triggered by a malicious X server to cause a crash in attached X clients. The issue is tracked as CWE-125 and has a CVSS 3.1 base score of 5.1, indicating a medium severity. The attack vector is local (AV:L), requiring low attack complexity and no privileges or user interaction. The impact is limited to confidentiality loss (C:L) and availability loss (A:L), with no integrity impact.

CWE-125Out-of-bounds Read (opens in a new tab)
Base weaknessCWE Top 25 (2025): #8
The product reads data past the end, or before the beginning, of the intended buffer.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design · Language Selection
Use a language that provides appropriate memory abstractions.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Overread Buffers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

gitlab.freedesktop.org/xorg/lib/libx11/-/merge_requests/310/diffs?commit_id=980868483446f24f9658d26aa5bfa42f3da6dd3a (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 5 Oct 2026, 20:38 UTC

WeaknessesCWE-125

Technical details

References

Community reviews

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