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

published 2026-07-06 4 mo ago modified 2026-10-25 14 d ago also EUVD-2026-41912

cvss: 3.8; version 3.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 9%
public exploits: 0; none known

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.

Patch / fix

links 1

github.com/OP-TEE/optee_os/security/advisories/GHSA-fcm8-vjhf-6vqh advisory

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-53763 updated 2026-07-07 cvss 6.5

OP-TEE: OP-TEE: Data integrity compromise due to integer overflow in AES-GCM

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 4 mo ago (2026-07-07)

Exploit prediction

0.19% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.0	3.8	CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N

Affected products

OP-TEE optee_os

Classification

Weakness

CWE-190 Integer Overflow or Wraparound

References

github.com /OP-TEE/optee_os/security/advisories/GHSA-fcm8-vjhf-6vqh
vendor-advisory, patch

Sources

CVE List CVE-2026-53763
NVD CVE-2026-53763

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary