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.

CSIRTS triage

What: A heap-based buffer overflow vulnerability exists in libexpat due to mishandling of reallocation.
Who is affected: Deployments of libexpat before version 2.8.2 are affected by this vulnerability.
Urgency: Remediation is medium priority due to the CVSS score of 6.9 indicating moderate risk.
Action: Upgrade libexpat to version 2.8.2 or later to mitigate this vulnerability.

AI-assisted analysis generated from the source advisory — verify against the original.

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EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-561320.11% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 1% of all EPSS-scored CVEs.

CVE	CSIRTS overview	External
CVE-2026-56132	coverage & exploitation status	NVD · CVE.org

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