xmlsoft libxml2 up to 2.15.3 NXT macro xmlFAParsePosCharGroup out-of-bounds

CVSS Meta Temp Score
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CTI Interest Score
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5.3$0-$5k0.00

Summaryinfo

A vulnerability described as critical has been identified in xmlsoft libxml2 up to 2.15.3. The impacted element is the function xmlFAParsePosCharGroup of the component NXT macro. Executing a manipulation can lead to out-of-bounds. This vulnerability appears as CVE-2026-86137. The attack may be performed from remote. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability has been found in xmlsoft libxml2 up to 2.15.3 and classified as critical. This vulnerability affects the function xmlFAParsePosCharGroup of the component NXT macro. The manipulation with an unknown input leads to a out-of-bounds vulnerability. The CWE definition for the vulnerability is CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In libxml2 before 2.15.4, xmlFAParsePosCharGroup has an out-of-bounds read, aka an out-of-bounds read in the NXT macro in xmlregexp.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-86137 since 09/05/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 343099 (Linux Distros Unpatched Vulnerability : CVE-2026-86137), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.15.4 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (343099). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Vendor

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.3

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 6.1
NVD Vector: 🔒

CNA Base Score: 2.9
CNA Vector (MITRE): 🔒

CVSSv2info

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

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 343099
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-86137

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: libxml2 2.15.4

Timelineinfo

09/05/2026 Advisory disclosed
09/05/2026 +0 days CVE reserved
09/05/2026 +0 days VulDB entry created
09/16/2026 +11 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-86137 (🔒)
GCVE (CVE): GCVE-0-2026-86137
GCVE (VulDB): GCVE-100-399208

Entryinfo

Created: 09/05/2026 06:35
Updated: 09/16/2026 06:01
Changes: 09/05/2026 06:35 (66), 09/05/2026 23:10 (2), 09/16/2026 06:01 (11)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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