CVE-2026-86140
Description
A flaw was found in libxml2. A local attacker could exploit a stack-based buffer overflow in the xmlSnprintfElements function to achieve arbitrary code execution. This vulnerability in a fundamental system library could lead to significant system compromise if successfully exploited.
Statement
This Important flaw in libxml2 allows a local attacker to achieve arbitrary code execution due to a stack-based buffer overflow. While requiring local access, the vulnerability's presence in a fundamental system library could lead to significant system compromise if exploited.
Mitigation
To mitigate this, administrators should disable DTD processing and validation for untrusted documents within libxml2 parsers and restrict network access so only authorized users can submit XML data to the application. For robust defense-in-depth against buffer overflow exploitation, ensure the library and dependent applications are compiled with memory safety flags like stack canaries (-fstack-protector-strong) and bounds checking (_FORTIFY_SOURCE=2), while verifying that standard OS-level protections such as ASLR and Data Execution Prevention (NX/XD Bit) are active on the host system.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.4 | N/A | 8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | High | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | Low |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
Understanding the Weakness (CWE)
Integrity,Confidentiality,Availability
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of the product's implicit security policy. This can often be used to subvert any other security service.
Availability
Technical Impact: Modify Memory; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU)
Buffer overflows generally lead to crashes. Other attacks leading to lack of availability are possible, including putting the product into an infinite loop.
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