CVE-2026-56409: CWE-190 Integer Overflow or Wraparound in libexpat project libexpat
xmlwf in libexpat before 2.8.2 has an integer overflow for the output filename when -d outputDir is used.
AI Analysis
Technical Summary
CVE-2026-56409 describes an integer overflow (CWE-190) in the xmlwf utility of the libexpat project versions prior to 2.8.2. The overflow occurs during the computation of the output filename when the -d outputDir option is used, potentially leading to memory corruption or other impacts. The vulnerability has not been confirmed as exploited in the wild, and no official remediation or patch information is currently available.
Potential Impact
Successful exploitation could result in high confidentiality and integrity impact, with limited availability impact, as indicated by the CVSS vector. The integer overflow may allow an attacker to manipulate memory or cause unexpected behavior in xmlwf when processing output filenames, potentially leading to code execution or data corruption under certain conditions.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, avoid using the -d outputDir option with vulnerable versions of xmlwf or restrict usage to trusted inputs. Monitor official libexpat project communications for updates and patches.
CVE-2026-56409: CWE-190 Integer Overflow or Wraparound in libexpat project libexpat
Description
xmlwf in libexpat before 2.8.2 has an integer overflow for the output filename when -d outputDir is used.
CVSS v3.1
Score 6.5medium
Affected software
Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-56409 describes an integer overflow (CWE-190) in the xmlwf utility of the libexpat project versions prior to 2.8.2. The overflow occurs during the computation of the output filename when the -d outputDir option is used, potentially leading to memory corruption or other impacts. The vulnerability has not been confirmed as exploited in the wild, and no official remediation or patch information is currently available.
Potential Impact
Successful exploitation could result in high confidentiality and integrity impact, with limited availability impact, as indicated by the CVSS vector. The integer overflow may allow an attacker to manipulate memory or cause unexpected behavior in xmlwf when processing output filenames, potentially leading to code execution or data corruption under certain conditions.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, avoid using the -d outputDir option with vulnerable versions of xmlwf or restrict usage to trusted inputs. Monitor official libexpat project communications for updates and patches.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mitre
- Date Reserved
- 2026-06-21T15:52:59.313Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a380caeeed863c81e0981b3
Added to database: 06/21/2026, 16:09:18 UTC
Last enriched: 06/28/2026, 21:55:21 UTC
Last updated: 08/05/2026, 12:41:16 UTC
Views: 107
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
External Links
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.