CVE-2026-56409
published 2026-06-21CVE-2026-56409: xmlwf in libexpat before 2.8.2 has an integer overflow for the output filename when -d outputDir is used.
PriorityP428medium6.5CVSS 3.1
AVLACHPRNUIRSUCHIHAL
EPSS
0.12%
1.8th percentile
xmlwf in libexpat before 2.8.2 has an integer overflow for the output filename when -d outputDir is used.
Affected
2 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| libexpat_project | libexpat | < 2.8.2 | 2.8.2 |
| ubuntu | expat | — | — |
CVSS provenance
nvdv3.16.5MEDIUMCVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L
vendor_ubuntu4.9MEDIUM
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
GHSA
xmlwf in libexpat before 2.8.2 has an integer overflow for the output filename when -d outputDir is used.
ghsa_unreviewed·2026-06-21
CVE-2026-56409 [MEDIUM] CWE-190 xmlwf in libexpat before 2.8.2 has an integer overflow for the output filename when -d outputDir is used.
xmlwf in libexpat before 2.8.2 has an integer overflow for the output filename when -d outputDir is used.
VulDB
libexpat up to 2.8.1 integer overflow (EUVD-2026-38186)
vuldb·2026-06-21·CVSS 6.5
CVE-2026-56409 [MEDIUM] libexpat up to 2.8.1 integer overflow (EUVD-2026-38186)
A vulnerability was found in libexpat up to 2.8.1. It has been classified as problematic. The impacted element is an unknown function. This manipulation causes integer overflow.
This vulnerability appears as CVE-2026-56409. The attack requires local access. There is no available exploit.
Upgrading the affected component is recommended.
Ubuntu
Expat vulnerabilities
vendor_ubuntu·2026-09-24·CVSS 4.9
CVE-2026-56410 [MEDIUM] Expat vulnerabilities
Title: Expat vulnerabilities
Summary: Expat could be made to crash or run programs if it received specially
crafted input.
It was discovered that Expat did not correctly handle certain integer
arithmetic. An attacker could possibly use this issue to cause a denial of
service.
(CVE-2026-56406, CVE-2026-56407, CVE-2026-56409, CVE-2026-56410, CVE-2026-56411)
It was discovered that Expat did not correctly track handler call depth. An
attacker could possibly use this issue to cause Expat to crash or execute
arbitrary code. (CVE-2026-56131)
It was discovered that Expat did not correctly handle certain memory
operations. An attacker could possibly use this issue to cause Expat to
crash or execute arbitrary code. (CVE-2026-56132)
It was discovered that Expat did not correctly handle certain U
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2026-06-21
Published