Vulnerability in optee-os (UBUNTU-CVE-2026-42546)

Summary

Vulnerability in optee-os (UBUNTU-CVE-2026-42546). Risk of unauthorized operations or information disclosure. Exploitable via OPTEE_MSG_ATTR_TYPE_MASK.

Original description

The description as published by the source.

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. Starting in version 3.3.0 and prior to version 4.11.0, a resource leak exists in OP-TEE’s shared memory cleanup logic because the function cleanup_shm_refs() in core/tee/entry_std.c fails to apply a required bitmask (OPTEE_MSG_ATTR_TYPE_MASK) to parameter attributes. When processing non-contiguous memory parameters from a normal-world caller, the system fails to match the attribute type in its internal switch statement and skips the necessary mobj_put() call. This results in a persistent reference leak of mobj_reg_shm objects, which remain on internal lists with dangling refcounts. This affects non-FF-A configurations that support non-contiguous, non-secure shared memory. Over time, these accumulated leaks progressively consume the secure-world heap, degrading the system's ability to service trusted application operations and eventually requiring a reboot to recover. Version 4.11.0 contains a patch. No known workarounds are available.

Source: OSV.dev (Open Source Vulnerabilities) OSV

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as UBUNTU-CVE-2026-42546 has been found in optee-os.
Attackers can target a specific entry point like OPTEE_MSG_ATTR_TYPE_MASK over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "optee-os UBUNTU-CVE-2026-42546" on the vendor's site.

UBUNTU-CVE-2026-42546 (optee-os)
Attack vector: local / no user interaction
Attack surface: OPTEE_MSG_ATTR_TYPE_MASK / mobj_reg_shm
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (unclassified) exists in optee-os. Attackers reach the vulnerable code path via OPTEE_MSG_ATTR_TYPE_MASK.

📍 Affected scope

Check the vendor advisory for the affected versions of optee-os. Attack surface: OPTEE_MSG_ATTR_TYPE_MASK / mobj_reg_shm.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to the patched release per vendor advisory.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'optee-os' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
grep -r 'optee-os' . | grep -v node_modules
```
リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で optee-os を grep し、稼働しているサービス・バージョンを把握する。
2
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Affected packages

Ubuntu:25.10 optee-os

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Ubuntu:26.04:LTS optee-os

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Ubuntu:26.10 optee-os

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

References

report ubuntu.com
report cve.org
report github.com