A flaw was found in libtpms, a library that provides software TPM 2.0 emulation. When restoring TPM 2.0 state (for example during a virtual machine's power-on or state/migration restore), a malformed state blob can supply an oversized skip-block length that is not validated against the remaining size of the input buffer. This can drive an internal size counter negative, which bypasses a subsequent bounds check due to an unsafe signed-to-unsigned conversion, causing the parser to read memory outside the bounds of the heap buffer holding the state data. Successful exploitation can crash the process hosting libtpms (such as swtpm), resulting in a denial of service of the emulated TPM device and the virtual machine that depends on it. No data corruption or information disclosure was confirmed.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No mitigation is currently available that meets Red Hat Product Security's standards for usability, deployment, applicability, or stability.
References
History
Fri, 04 Sep 2026 18:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | A flaw was found in libtpms, a library that provides software TPM 2.0 emulation. When restoring TPM 2.0 state (for example during a virtual machine's power-on or state/migration restore), a malformed state blob can supply an oversized skip-block length that is not validated against the remaining size of the input buffer. This can drive an internal size counter negative, which bypasses a subsequent bounds check due to an unsafe signed-to-unsigned conversion, causing the parser to read memory outside the bounds of the heap buffer holding the state data. Successful exploitation can crash the process hosting libtpms (such as swtpm), resulting in a denial of service of the emulated TPM device and the virtual machine that depends on it. No data corruption or information disclosure was confirmed. | |
| Title | Libtpms: libtpms: heap out-of-bounds read in tpm2 state unmarshalling via unchecked block_skip_read() blocksize | |
| First Time appeared |
Redhat
Redhat enterprise Linux |
|
| Weaknesses | CWE-125 | |
| CPEs | cpe:/o:redhat:enterprise_linux:10 cpe:/o:redhat:enterprise_linux:8 cpe:/o:redhat:enterprise_linux:9 |
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| Vendors & Products |
Redhat
Redhat enterprise Linux |
|
| References |
| |
| Metrics |
cvssV3_1
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Projects
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Status: PUBLISHED
Assigner: redhat
Published:
Updated: 2026-09-04T18:51:12.453Z
Reserved: 2026-09-04T15:19:09.987Z
Link: CVE-2026-85769
No data.
Status : Received
Published: 2026-09-04T18:18:07.153
Modified: 2026-09-04T19:17:34.020
Link: CVE-2026-85769
No data.
OpenCVE Enrichment
Updated: 2026-09-04T20:15:14Z
Weaknesses