CVE-2025-49794
Description
A use-after-free vulnerability was found in libxml2. This issue occurs when parsing XPath elements under certain circumstances when the XML schematron has the <sch:name path="..."/> schema elements. This flaw allows a malicious actor to craft a malicious XML document used as input for libxml, resulting in the program's crash using libxml or other possible undefined behaviors.
Statement
This issue was rated with a severity impact of Important by Red Hat Product Security, as libxml can be used to parse XML coming from the network depending on how the program consumes it and uses the library. Additionally, although the initial report shows a crash due to invalid memory access (A:H), other undefined issues that can present data integrity due to the application overwriting sensitive data are not discarded (I:H).
Mitigation
There's no available mitigation other than avoid processing untrusted XML documents before updating to the libxml version containing the fix.
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 | 9.1 | N/A | 9.1 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
If the expired pointer is used in a read operation, an attacker might be able to control data read in by the application.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If the expired pointer references a memory location that is not accessible to the product, or points to a location that is "malformed" (such as NULL) or larger than expected by a read or write operation, then a crash may occur.
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If the expired pointer is used in a function call, or points to unexpected data in a write operation, then code execution may be possible.
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