MEDIUM
CVE-2026-56409
CWE-190Published: June 21, 2026· Updated: Jun 23, 2026
6.5
CVSS v3.1
EPSS:0.10%probability of exploitation in 30 daysPercentile:1.0th
Official Description
xmlwf in libexpat before 2.8.2 has an integer overflow for the output filename when -d outputDir is used.
Technical Analysis
CVE-2026-56409 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), with a CVSS base score of 6.5.
CVSS v3.1 Vector Breakdown
Exploitability
Attack VectorLocal
Attack ComplexityHigh
Privileges Req.None
User InteractionRequired
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityLow
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L
Affected Vendors & Products
libexpat_project1 product
libexpat
Source: NVD CPE · 1 total CPE entries
Exploit & PoC Resources
NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.
Official Patches & Advisories
All References (1)
→
https://github.com/libexpat/libexpat/pull/1259Patch · Issue Tracking
Quick Facts
CVE IDCVE-2026-56409
CVSS Score6.5 / 10
SeverityMEDIUM
WeaknessCWE-190
CISA KEVNo
EPSS (30d)0.10%
Affected1 vendor
PublishedJun 21, 2026
Related CVEs (CWE-190)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-56409 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.