CVE-2026-42546

Home/CVE/OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Corte

CVE

↯ PDF report

OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Corte

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.

LOW · CVSS 3.8 EPSS 0.00105

EPSS exploitation odds0.10% · top 98%

Monitor

No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence

No Sigma yet — build one → YARA rules0

Look this up elsewhere - one-click external pivots

NVD CVE.org CISA Exploit-DB GitHub PoC VulnCheck KEV GreyNoise

▸ How to read a CVE - triage first, then detect and patch

This page is every public fact about CVE-2026-42546, cross-linked. Its job is to answer one question fast - does this need my attention now? - and then hand you the two things you do about it. Here is how an analyst reads it.

Triage: should I act now? Four signals, and they are not interchangeable:

CVSSseverity - how bad it is IF exploited, 0-10. A high CVSS alone is not urgency; a flaw can be a perfect 10 and never actually be attacked. EPSSprobability - a model’s estimate of the chance it is exploited in the next 30 days, 0-1. This is the “will it actually happen” signal. CISA KEVconfirmed - it is being exploited in the wild right now. The strongest signal on the page; KEV beats any score. Weaponisedavailability - public exploits / PoCs, and especially Metasploit modules rated Excellent / Great. Reliable, packaged exploit code means low-skill attackers can use it today.

How they combine: KEV, or a dependable Metasploit module, means patch now regardless of CVSS. High CVSS + low EPSS + no exploit is real but not an emergency - schedule it. Low CVSS but KEV-listed still gets patched now. The verdict above already weighed these for you; this is how it got there.

Then what - two workflows:

Detectwhen you cannot patch today, follow this CVE to the ATT&CK techniques it enables, then Build a SIEM detection (the green button) - author a rule, test it in Atomic, deploy it. That buys visibility while the patch waits. PatchAffected products / packages tell you if you are exposed; Fixed versions by distribution and Vendor advisories give the exact version that closes it.

Reading order for the panels below: verdict + badges, then Public exploits / Metasploit (is it weaponised), then ATT&CK techniques + Sigma / IDS rules (can I detect it), then Affected products / packages + Fixed versions (am I exposed, what patches it), then Threat actors / IOCs (who uses it), then Scoring & timeline / references (the evidence).

▣

Severity & exploitation scoring

View on NVD →

CVSS base score

3.8

LOWCVSS v3.1 · [email protected]

EPSS exploitation probability

0.10%

Top 98%odds of exploitation in the next 30 days

CVSS metric silhouette

shape grows toward worst-case

SSVC triage · cisa-vulnrichment

Exploitation

none

Automatable

Tech impact

partial

CVSS vector breakdown

Exploitability - how they get in

Attack Vector

Network Adjacent Local Physical

Attack Complexity

Low High

Privileges Required

None Low High

User Interaction

None Required

Scope

Unchanged Changed

Impact - what breaks

Confidentiality

None Low High

Integrity

None Low High

Availability

None Low High

VECTORCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:L

Attack path

Full kill chain

→

◆

ATT&CK techniques

Techniques this CVE enables. Pills with a solid outline are high confidence - named directly in ATT&CK or Nuclei, or human-curated by CTID; the rest are inferred from the weakness type using MITRE's CVE Mapping Methodology and the CWE → CAPEC chain. Broad, generic-weakness guesses are filtered out. A small N× marks a technique that N independent sources agree on.

T1498.001 · Direct Network Flood T1498.002 · Reflection Amplification T1499 · Endpoint Denial of Service T1499.001 · OS Exhaustion Flood T1499.002 · Service Exhaustion Flood T1499.003 · Application Exhaustion Flood

▤ Build a SIEM detection for these techniques