CVE-2026-33317 OP-TEE: PKCS#11 TA out-of-bounds read and memory disclosure
Attackers can trigger out-of-bounds reads and writes in the PKCS#11 Trusted Application, leading to memory disclosure or crashes.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-33317?
CVE-2026-33317 is a high-severity memory corruption vulnerability in OP-TEE optee_os, published on 24 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. In versions 3.13.0 through 4.10.0, missing checks in `entry_get_attribute_value()` in `ta/pkcs11/src/object.c` can lead to out-of-bounds read from the PKCS#11 TA heap or a crash. When chained with the OOB read, the PKCS#11 TA function `PKCS11_CMD_GET_ATTRIBUTE_VALUE` or `entry_get_attribute_value()` can, with a bad template parameter, be tricked into reading at most 7 bytes beyond the end of the template buffer and writing beyond the end of the template buffer with the content of an attribute value of a PKCS#11 object. Commits e031c4e562023fd9f199e39fd2e85797e4cbdca9, 16926d5a46934c46e6656246b4fc18385a246900, and 149e8d7ecc4ef8bb00ab4a37fd2ccede6d79e1ca contain patches and are anticipated to be part of version 4.11.0.
Which versions are affected by CVE-2026-33317?
It affects 1 product.
Products include Trustedfirmware Op-Tee.
How do I fix CVE-2026-33317?
No fix has been published for CVE-2026-33317 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-33317 being exploited?
There is no known exploitation of CVE-2026-33317 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in OP-TEE optee_os
Sources
Also known as DEBIAN-CVE-2026-33317, GHSA-8cqw-mg7v-c9p9, UBUNTU-CVE-2026-33317.