Threats Tagged 'cve-2026-34876'

An out-of-bounds read vulnerability exists in Mbed TLS versions 3.x prior to 3.6.6 in the function mbedtls_ccm_finish(). This flaw allows attackers to read adjacent CCM context data when using the multipart CCM API with an oversized tag length parameter. The vulnerability is identified as CWE-125 (out-of-bounds read). No CVSS score or known exploits in the wild are reported. Affected versions include Mbed TLS 3.0 and related builds. No patch information is provided in the available data.

CVE-2026-34876 is an out-of-bounds read vulnerability in Mbed TLS 3.x before 3.6.6 affecting the multipart CCM API. The vulnerability arises from missing validation of the tag_len parameter in the mbedtls_ccm_finish() function, allowing attackers to read adjacent CCM context data. In Mbed TLS 4.x, the internal implementation has the same issue, but the vulnerable function is not exposed in the public API. Exploitation requires direct application-level use of the multipart CCM API with an oversized tag_len. This vulnerability has a high severity with a CVSS score of 7.5 and impacts confidentiality but not integrity or availability.