Vulnerability · Published Jul 6, 2026 · Assigned by GitHub_M

CVE-2026-53763OP-TEE has AES-GCM 32-bit integer overflow in length counters that breaks authentication guarantee

Low 3.8

In plain English

A low-severity integer overflow in optee_os from OP-TEE. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 9% of all known vulnerabilities).

Severity (CVSS 3.0)3.8Low

Exploit odds (30 days)0.2%top 90.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

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. Starting in version 3.0.0 and prior to version 4.11.0, 32-bit integer overflows in OP-TEE core's AES-GCM implementation cause the authentication tag to be computed with incorrect bit-length values after processing more than 512 megabytes of payload or Additional Authenticated Data (AAD). Version 4.11.0 contains a patch. No known workarounds are available.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:13	optee-os	no fix listed	DEBIAN-CVE-2026-53763
Ubuntu:25.10	optee-os	no fix listed	UBUNTU-CVE-2026-53763
Ubuntu:26.04:LTS	optee-os	no fix listed	UBUNTU-CVE-2026-53763
Ubuntu:26.10	optee-os	no fix listed	UBUNTU-CVE-2026-53763

Affected products (as reported)

Vendor	Product	Versions
OP-TEE	optee_os	>= 3.0.0, < 4.11.0

Weakness: CWE-190 · Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N

References

https://github.com/OP-TEE/optee_os/security/advisories/GHSA-fcm8-vjhf-6vqh x_refsource_CONFIRM