SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-56132

In libexpat before 2.8.2, there is a heap-based buffer overflow in doProlog in xmlparse.c because scaffold backing array reallocation is mishandled when there is data-structure sharing across parsers.

MEDIUM 6.9EPSS 0.10%

Does this matter?

Lower severity and a low EPSS score (0.10%). Track it; it rarely justifies an emergency change on its own.

Description

In libexpat before 2.8.2, there is a heap-based buffer overflow in doProlog in xmlparse.c because scaffold backing array reallocation is mishandled when there is data-structure sharing across parsers.

CVSS 3.1
6.9 MEDIUMCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L
EPSS
0.10% probability · 1th percentile
CISA KEV
Not listed
Weakness
CWE-821
Affected
libexpat project/libexpat
Source
cve@mitre.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.