Is CVE-2026-29078 in the CISA KEV catalog?

No. CVE-2026-29078 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-29078?

CVE-2026-29078 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2026-29078?

CVE-2026-29078 has an EPSS score of 0.27% (18th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2026-29078

HIGH

7.5

CVSS v3

NVD

Description

Lexbor is a web browser engine library. Prior to 2.7.0, the ISO‑2022‑JP encoder in Lexbor fails to reset the temporary size variable between iterations. The statement ctx->buffer_used -= size with a stale size = 3 causes an integer underflow that wraps to SIZE_MAX. Afterwards, memcpy is called with a negative length, leading to an out‑of‑bounds read from the stack and an out‑of‑bounds write to the heap. The source data is partially controllable via the contents of the DOM tree. This vulnerability is fixed in 2.7.0.

CWE-191 CWE-787Out-of-bounds Write

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploit Intelligence

0.27%probability of exploitation in 30 days

18thpercentile

Low risk: more likely to be exploited than 18% of all known CVEs.

References

https://github.com/lexbor/lexbor/security/advisories/GHSA-mrwr-xh7f-96v3

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-03-18.