CVE-2026-76641

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.35% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 28.7% of scored records. A rank, not a probability.

NVD base score

8.7 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

NVD analysis status

Awaiting Analysis. NVD last modified this record on 2026-10-26.

Red Hat severity

Important. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-08-20 17:31Z2 MO AGO

Last updated

2026-10-01 15:21Z28 DAYS AGO

Reserved

2026-08-19

Assigning CNA

VulnCheck

Record state

PUBLISHED

Severity

High (CVSS 8.7)

CNA CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Weaknesses

• CWE-125Out-of-bounds ReadBase

Data version

5.2

Document digest

423f24272975cdc0f0dc4c49297078366a83121bcba102113b3012964c04e4e9

• github.comPull Requesthttps://github.com/libexpat/libexpat/pull/1331issue-tracking
• github.comPatch Commithttps://github.com/libexpat/libexpat/commit/98599f6dcc2b460410881fe420f5f55d6bec63bfpatch
• www.vulncheck.comhttps://www.vulncheck.com/advisories/expat-out-of-bounds-read-via-dtdcopythird-party-advisory