Out-of-bounds write in tpm2-tss - CVE-2026-73987
Published: November 4, 2026
Vulnerability identifier: #VU159298
CSH Severity: Low
CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-73987
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 potentially execute arbitrary code in the context of the calling process.
The vulnerability exists due to an out-of-bounds write in the tpm2-tss iesys_MU_IESYS_SESSION_Unmarshal function when deserializing attacker-controlled ESYS_TR or context blobs through Esys_TR_Deserialize or Esys_ContextLoad. A local user can supply a crafted blob with a sizeSessionValue field exceeding the capacity of the fixed-size sessionValue buffer to overwrite adjacent memory and potentially execute arbitrary code.
Affected software
tpm2-tss
How to mitigate CVE-2026-73987
Install security update from vendor's website.
tpm2-tss - addressed in versions 4.1.4, 4.2.0