x.org libX11 up to 1.8.13 XkbGetMap buffer overflow

CVSS Meta Temp Score
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CTI Interest Score
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6.7$0-$5k1.23

Summaryinfo

A vulnerability described as critical has been identified in x.org libX11 up to 1.8.13. Affected by this issue is some unknown functionality of the component XkbGetMap Handler. Executing a manipulation can lead to buffer overflow. This vulnerability is tracked as CVE-2026-88806. The attack can be launched remotely. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in x.org libX11 up to 1.8.13. It has been declared as critical. This vulnerability affects an unknown code block of the component XkbGetMap Handler. The manipulation with an unknown input leads to a buffer overflow vulnerability. The CWE definition for the vulnerability is CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

A malicious X server could exploit a buffer overflow in libX11 before 1.8.14 during handling of XkbGetMap overflowing the key_sym_map.

The advisory is shared for download at gitlab.freedesktop.org. This vulnerability was named CVE-2026-88806 since 09/10/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available.

Upgrading to version 1.8.14 eliminates this vulnerability.

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Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.9
VulDB Meta Temp Score: 6.7

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.5
CNA Vector (suse): 🔒

CVSSv2info

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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Buffer overflow
CWE: CWE-120 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: libX11 1.8.14

Timelineinfo

09/10/2026 CVE reserved
09/21/2026 +11 days Advisory disclosed
09/21/2026 +0 days VulDB entry created
09/21/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: x.org

Advisory: gitlab.freedesktop.org
Status: Confirmed

CVE: CVE-2026-88806 (🔒)
GCVE (CVE): GCVE-0-2026-88806
GCVE (VulDB): GCVE-100-408112

Entryinfo

Created: 09/21/2026 15:53
Changes: 09/21/2026 15:53 (63)
Complete: 🔍
Cache ID: 216::103

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