# 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.

- **Severity:** High 8.7 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 24 Apr 2026
- **Updated:** 24 Apr 2026
- **Also known as:** DEBIAN-CVE-2026-33317, GHSA-8cqw-mg7v-c9p9, UBUNTU-CVE-2026-33317

## 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.

Weakness: CWE-787 (Out-of-bounds Write), CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-33317?

It affects 1 product.


Products: 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.

## 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:

- PoC for CVE-2026-33317 OP-TEE PKCS#11 TA out-of-bounds write (github_poc): https://github.com/0xbbdd/CVE-2026-33317

## Other vulnerabilities in OP-TEE optee_os

- [CVE-2019-1010292](https://insights.sbomify.com/CVE-2019-1010292/): Memory corruption in OP-TEE (critical 9.8)
- [CVE-2019-1010293](https://insights.sbomify.com/CVE-2019-1010293/): Memory corruption in OP-TEE (critical 9.8)
- [CVE-2019-1010295](https://insights.sbomify.com/CVE-2019-1010295/): Linaro/OP-TEE OP-TEE 3.3.0 and earlier is affected by: Buffer Overflow. (critical 9.8)
- [CVE-2019-1010296](https://insights.sbomify.com/CVE-2019-1010296/): Memory corruption in OP-TEE (critical 9.8)
- [CVE-2019-1010297](https://insights.sbomify.com/CVE-2019-1010297/): Memory corruption in OP-TEE (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33317 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-33317 in the wild and no public exploit code.

Affected product: OP-TEE optee_os. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-33317/ (Markdown: https://insights.sbomify.com/CVE-2026-33317/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33317
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33317
- OSV: https://osv.dev/vulnerability/CVE-2026-33317

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33317/
Summaries are generated and may contain mistakes; the official description above is the record.