CVE-2026-50219: CWE-416 Use After Free in libexpat project libexpat
CVE-2026-50219 is a use-after-free vulnerability in libexpat versions before 2. 8. 2. It arises because the library lacks proper handler call depth tracking when certain XML parsing functions are called from within handlers during policy violations. This flaw can lead to memory corruption issues. The vulnerability has a CVSS score of 4. 9, indicating medium severity. No official patch or remediation guidance is currently confirmed. There are no known exploits in the wild at this time.
AI Analysis
Technical Summary
The libexpat XML parsing library before version 2.8.2 does not track handler call depth for calls to XML_GetBuffer, XML_Parse, XML_ParseBuffer, XML_ParserFree, or XML_ParserReset when these are invoked from within handlers during policy violations. This lack of tracking can cause a use-after-free condition, classified under CWE-416. The vulnerability has a CVSS 3.1 base score of 4.9 (AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L), reflecting local attack vector with high attack complexity and limited impact on confidentiality, integrity, and availability. No patch or official remediation level is currently documented.
Potential Impact
The vulnerability can result in use-after-free memory corruption, potentially leading to limited confidentiality, integrity, and availability impacts. The attack requires local access with high complexity and no privileges or user interaction. There are no known active exploits reported.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, avoid invoking the affected XML parsing functions from within handlers in ways that could trigger policy violations. Monitor libexpat project communications for updates on patches or mitigations.
CVE-2026-50219: CWE-416 Use After Free in libexpat project libexpat
Description
CVE-2026-50219 is a use-after-free vulnerability in libexpat versions before 2. 8. 2. It arises because the library lacks proper handler call depth tracking when certain XML parsing functions are called from within handlers during policy violations. This flaw can lead to memory corruption issues. The vulnerability has a CVSS score of 4. 9, indicating medium severity. No official patch or remediation guidance is currently confirmed. There are no known exploits in the wild at this time.
CVSS v3.1
Score 4.9medium
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The libexpat XML parsing library before version 2.8.2 does not track handler call depth for calls to XML_GetBuffer, XML_Parse, XML_ParseBuffer, XML_ParserFree, or XML_ParserReset when these are invoked from within handlers during policy violations. This lack of tracking can cause a use-after-free condition, classified under CWE-416. The vulnerability has a CVSS 3.1 base score of 4.9 (AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L), reflecting local attack vector with high attack complexity and limited impact on confidentiality, integrity, and availability. No patch or official remediation level is currently documented.
Potential Impact
The vulnerability can result in use-after-free memory corruption, potentially leading to limited confidentiality, integrity, and availability impacts. The attack requires local access with high complexity and no privileges or user interaction. There are no known active exploits reported.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, avoid invoking the affected XML parsing functions from within handlers in ways that could trigger policy violations. Monitor libexpat project communications for updates on patches or mitigations.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mitre
- Date Reserved
- 2026-06-04T04:20:31.953Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a210e2ee29bf47b506be55e
Added to database: 6/4/2026, 5:33:34 AM
Last enriched: 6/4/2026, 5:48:44 AM
Last updated: 6/4/2026, 7:44:47 AM
Views: 11
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