What’s Vulnerable › Vulnerabilities

CVE-2026-75900: Swtpm: swtpm: out-of-bounds read in swtpm_nvram_checkheader due to sizeof(pointer) vs sizeof(struct) mismatch

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-19 · updated 2026-08-21
• Weakness: CWE-125

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.

Affected products

• Red Hat Enterprise Linux 10: all versions
• Red Hat Enterprise Linux 8: all versions
• Red Hat Enterprise Linux 9: all versions

References

• https://access.redhat.com/security/cve/CVE-2026-75900
• https://bugzilla.redhat.com/show_bug.cgi?id=2517910

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