CVE-2026-75900

Name	CVE-2026-75900
Description	An out-of-bounds read vulnerability was found in swtpm's SWTPM_NVRAM_CheckHeader() function. The entry guard checks the buffer length against sizeof(bh), where bh is a pointer, instead of sizeof(*bh), the actual struct size. This allows an undersized buffer to pass validation, causing a 2-byte heap overread on 64-bit systems (6 bytes on 32-bit) when accessing the totlen field. This may cause daemon termination on some platforms and leaks heap data to the log.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1144810

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
swtpm (PTS)	bookworm	0.7.1-1.3	vulnerable
	trixie	0.7.1-1.5	vulnerable
	forky, sid	0.10.2-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
swtpm	source	(unstable)	0.10.2-1			1144810

Notes

[trixie] - swtpm <no-dsa> (Minor issue)
[bookworm] - swtpm <postponed> (Minor issue)
https://github.com/stefanberger/swtpm/pull/1155
Fixed by: https://github.com/stefanberger/swtpm/commit/dc5f5ee3d8261a4d9814ad5da69164a118822401 (master)
Fixed by: https://github.com/stefanberger/swtpm/commit/afc9e512a0459b12776e8fa509cfa039908c6be6 (v0.10.2)
Fixed by: https://github.com/stefanberger/swtpm/commit/30454bc4f6b946fd6296534cccec95432446f8a2 (v0.7.5)