# CVE-2026-71967: OP-TEE OS 4.10.0 NULL Pointer Dereference DoS via Widevine PTA open_session

> Attackers can crash the Trusted Execution Environment by triggering a null pointer dereference in the Widevine PTA handler when enabled.

- **Severity:** Medium 5.7 (`CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **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:** 10 Aug 2026
- **Updated:** 14 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-71967, GHSA-cg97-7v4v-qg3v, UBUNTU-CVE-2026-71967

## What is CVE-2026-71967?

CVE-2026-71967 is a medium-severity vulnerability in OP-TEE optee_os, published on 10 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

OP-TEE OS through 4.10.0, fixed in commit 0aadfc2, contains a null pointer dereference vulnerability in the Widevine pseudo-TA open_session handler that allows Normal World clients to cause a denial of service when CFG_WIDEVINE_PTA is enabled. Attackers can open a session directly on the Widevine PTA to trigger an unconditional dereference of a NULL calling session pointer via is_user_ta_ctx(), faulting the TEE at S-EL1 and crashing the trusted execution environment.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-71967?


## How do I fix CVE-2026-71967?

No fix has been published for CVE-2026-71967 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-71967 being exploited?

There is no known exploitation of CVE-2026-71967 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-71967 and fix it if it is affected.

What it is: CVE-2026-71967 is a medium-severity vulnerability in OP-TEE optee_os, published on 10 Aug 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-2026-71967 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-2026-71967/ (Markdown: https://insights.sbomify.com/CVE-2026-71967/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-71967
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-71967
- OSV: https://osv.dev/vulnerability/CVE-2026-71967

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-71967/
Summaries are generated and may contain mistakes; the official description above is the record.