EUVD-2026-18356
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Lifecycle Timeline
3Description
An issue was discovered in Mbed TLS 3.x before 3.6.6. An out-of-bounds read vulnerability in mbedtls_ccm_finish() in library/ccm.c allows attackers to obtain adjacent CCM context data via invocation of the multipart CCM API with an oversized tag_len parameter. This is caused by missing validation of the tag_len parameter against the size of the internal 16-byte authentication buffer. The issue affects the public multipart CCM API in Mbed TLS 3.x, where mbedtls_ccm_finish() can be invoked directly by applications. In Mbed TLS 4.x versions prior to the fix, the same missing validation exists in the internal implementation; however, the function is not exposed as part of the public API. Exploitation requires application-level invocation of the multipart CCM API.
Analysis
Out-of-bounds read in Mbed TLS 3.x before 3.6.6 allows attackers to leak adjacent CCM context data through the multipart CCM API by passing an oversized tag_len parameter to mbedtls_ccm_finish(), which lacks validation against the internal 16-byte authentication buffer. Mbed TLS 4.x contains the same vulnerability in internal code but does not expose the vulnerable function publicly; exploitation requires direct application-level invocation of the affected API. …
Sign in for full analysis, threat intelligence, and remediation guidance.
Priority Score
Share
External POC / Exploit Code
Leaving vuln.today