CVE record · CVE-2026-13478

Out-of-bounds read in Zephyr ext2 block-bitmap validation from a crafted s_blocks_count

CVSS 5.5 MediumEPSS 0.0014 · 3rd percentile

Published by the CVE Program (CNA: zephyr) at 25 Aug 2026, 16:05 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
Vendor	Product	Versions
zephyrproject	zephyr Package name: zephyr https://github.com/zephyrproject-rtos/zephyr	affected 3.5.0 to before 4.3.2 semver affected 4.4.0 to before 4.4.2 semver Other versions: unaffected

Identifiers: CVE-2026-13478
CNA: zephyr
Weakness (CWE): CWE-125
Tags: zephyr
Memory corruption
Published: 25 Aug 2026
Updated: 4 Nov 2026

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
5.5	Medium	3.1	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H	CNA (zephyr)

CISA KEV Not listed.
EPSS 0.0014, the 3rd percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

25 Aug 2026, 16:05 UTC Confirmed by the CVE List
25 Aug 2026, 17:17 UTC Confirmed by NVD

Sources

References from the CNA

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.