How severe is CVE-2026-33662?

CVE-2026-33662 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-33662 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-33662?

CVE-2026-33662 affects Trustedfirmware Op-tee. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-33662?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-33662 have an EU (EUVD) identifier?

Yes. CVE-2026-33662 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-25592.

When was CVE-2026-33662 published?

CVE-2026-33662 was published on 2026-04-24 and last updated on 2026-06-17.

CVE-2026-33662

CVE-2026-33662 is a high-severity vulnerability in Trustedfirmware Op-tee with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-190.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 0% (32nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-25592
Weakness: CWE-190
Affected product: Trustedfirmware Op-tee
Published: 2026-04-24
Last modified: 2026-06-17

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. From 3.8.0 to 4.10, in the function emsa_pkcs1_v1_5_encode() in core/drivers/crypto/crypto_api/acipher/rsassa.c, the amount of padding needed, "PS size", is calculated by subtracting the size of the digest and other fields required for the EMA-PKCS1-v1_5 encoding from the size of the modulus of the key. By selecting a small enough modulus, this subtraction can overflow. The padding is added as a string of 0xFF bytes with a call to memset(), and an underflowed integer will cause the memset() call to overwrite until OP-TEE crashes. This only affects platforms registering RSA acceleration.

Frequently asked questions

What is CVE-2026-33662?: 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. From 3.8.0 to 4.10, in the function emsa_pkcs1_v1_5_encode() in core/drivers/crypto/crypto_api/acipher/rsassa.c, the amount of padding needed, "PS size", is calculated by subtracting the size of the digest and other fields required for the EMA-PKCS1-v1_5 encoding from the size of the modulus of the key. By selecting a small enough modulus, this subtraction can overflow. The padding is added as a string of 0xFF bytes with a call to memset(), and an underflowed integer will cause the memset() call to overwrite until OP-TEE crashes. This only affects platforms registering RSA acceleration.
How severe is CVE-2026-33662?: CVE-2026-33662 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-33662 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-33662?: CVE-2026-33662 affects Trustedfirmware Op-tee. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-33662?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-33662 have an EU (EUVD) identifier?: Yes. CVE-2026-33662 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-25592.
When was CVE-2026-33662 published?: CVE-2026-33662 was published on 2026-04-24 and last updated on 2026-06-17.

References

https://github.com/OP-TEE/optee_os/security/advisories/GHSA-4cf8-v5g3-73gr

Affected products (1)

cpe:2.3:o:trustedfirmware:op-tee:*:*:*:*:*:*:*:*

More vulnerabilities in Trustedfirmware Op-tee

CVE-2019-1010292 — Critical (CVSS 9.8): Linaro/OP-TEE OP-TEE Prior to version v3.4.0 is affected by: Boundary checks. The impact is: This could lead to…
CVE-2019-1010298 — Critical (CVSS 9.8): Linaro/OP-TEE OP-TEE 3.3.0 and earlier is affected by: Buffer Overflow. The impact is: Code execution in the context of…
CVE-2019-1010297 — Critical (CVSS 9.8): Linaro/OP-TEE OP-TEE 3.3.0 and earlier is affected by: Buffer Overflow. The impact is: Execution of code in TEE core…
CVE-2019-1010296 — Critical (CVSS 9.8): Linaro/OP-TEE OP-TEE 3.3.0 and earlier is affected by: Buffer Overflow. The impact is: Code execution in context of TEE…
CVE-2019-1010295 — Critical (CVSS 9.8): Linaro/OP-TEE OP-TEE 3.3.0 and earlier is affected by: Buffer Overflow. The impact is: Memory corruption and disclosure…
CVE-2019-1010293 — Critical (CVSS 9.8): Linaro/OP-TEE OP-TEE 3.3.0 and earlier is affected by: Boundary crossing. The impact is: Memory corruption of the TEE…

All CVEs affecting Trustedfirmware Op-tee →

Other CWE-190 (Integer Overflow or Wraparound) vulnerabilities

CVE-2026-4689 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This vulnerability was…
CVE-2026-24814 — Critical (CVSS 10.0): Integer Overflow or Wraparound vulnerability in swoole swoole-src (thirdparty/hiredis modules). This vulnerability is…
CVE-2025-64721 — Critical (CVSS 10.0): Sandboxie is a sandbox-based isolation software for 32-bit and 64-bit Windows NT-based operating systems. In versions…
CVE-2015-5108 — Critical (CVSS 10.0): Integer overflow in Adobe Reader and Acrobat 10.x before 10.1.15 and 11.x before 11.0.12, Acrobat and Acrobat Reader DC…
CVE-2015-5097 — Critical (CVSS 10.0): Integer overflow in Adobe Reader and Acrobat 10.x before 10.1.15 and 11.x before 11.0.12, Acrobat and Acrobat Reader DC…
CVE-2013-2555 — Critical (CVSS 10.0): Integer overflow in Adobe Flash Player before 10.3.183.75 and 11.x before 11.7.700.169 on Windows and Mac OS X, before…

Browse all CWE-190 (Integer Overflow or Wraparound) vulnerabilities →