Out-of-bounds write in tpm2-tss - CVE-2026-73989
Published: November 4, 2026
Vulnerability identifier: #VU159296
CSH Severity: Low
CVSS v4: 6.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-73989
CWE-ID: CWE-787
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to corrupt memory and cause a denial of service in applications that process attacker-controlled FAPI policies.
The vulnerability exists due to an out-of-bounds write in the ifapi_compute_policy_digest function in src/tss2-fapi/ifapi_helpers.c when computing policy digests using an unchecked PCR index. A local user can supply a crafted policy JSON containing pcrs entries with pcr >= 32 to write past the end of the pcrSelect array, corrupt memory in the calling process, and potentially crash the application.
Affected software
tpm2-tss
How to mitigate CVE-2026-73989
Install security update from vendor's website.
tpm2-tss - addressed in versions 4.1.4, 4.2.0