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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| OP-TEE | optee_os | >= 3.13.0, <= 4.10.0 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 13 | optee-os | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | optee-os | No fix yet | — |
| Ubuntu 26.04 LTS | optee-os | No fix yet | — |
| Ubuntu 25.10 | optee-os | No fix yet | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
GitHub 1 repository
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0xbbdd/CVE-2026-33317 ★ 0 · Apr 30, 2026
PoC for CVE-2026-33317 OP-TEE PKCS#11 TA out-of-bounds write
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
References
- https://github.com/OP-TEE/optee_os/security/advisories/GHSA-8cqw-mg7v-c9p9
- https://github.com/OP-TEE/optee_os/commit/149e8d7ecc4ef8bb00ab4a37fd2ccede6d79e1ca
- https://github.com/OP-TEE/optee_os/commit/16926d5a46934c46e6656246b4fc18385a246900
- https://github.com/OP-TEE/optee_os/commit/e031c4e562023fd9f199e39fd2e85797e4cbdca9