Out-of-bounds Read in Op-Tee Optee OS
CVE-2026-33317
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.
Vulnerability class: Buffer Overflow
EPSS: 0.002 (8.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.7 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L.
Affected products
- Op-tee Optee_os — versions >= 3.13.0, <= 4.10.0
- Trustedfirmware Op-tee
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Patch, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-33317?
- CVE-2026-33317 is a high-severity vulnerability in Op-Tee Optee OS, classified under Out-of-bounds Read. CVSS score: 8.7/10. Published 2026-04-24.
- How severe is CVE-2026-33317?
- High severity. CVSS v3 base score is 8.7 out of 10.
- Is CVE-2026-33317 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.