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.

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Linux Distros Unpatched Vulnerability : CVE-2026-34876

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - An issue was discovered in Mbed TLS 3.x before 3.6.6. An out-of-bounds read vulnerability in mbedtlsccmfinish in library/ccm.c allows attackers to obtain adjace...

EUVD-2026-18356

An issue was discovered in Mbed TLS 3.x before 3.6.6. An out-of-bounds read vulnerability in mbedtlsccmfinish in library/ccm.c allows attackers to obtain adjacent CCM context data via invocation of the multipart CCM API with an oversized taglen parameter. This is caused by missing validation of t...

DEBIAN-CVE-2026-34876

An issue was discovered in Mbed TLS 3.x before 3.6.6. An out-of-bounds read vulnerability in mbedtlsccmfinish in library/ccm.c allows attackers to obtain adjacent CCM context data via invocation of the multipart CCM API with an oversized taglen parameter. This is caused by missing validation of t...

UBUNTU-CVE-2026-34876

An issue was discovered in Mbed TLS 3.x before 3.6.6. An out-of-bounds read vulnerability in mbedtlsccmfinish in library/ccm.c allows attackers to obtain adjacent CCM context data via invocation of the multipart CCM API with an oversized taglen parameter. This is caused by missing validation of t...

CVE-2026-34876

An issue was discovered in Mbed TLS 3.x before 3.6.6. An out-of-bounds read vulnerability in mbedtlsccmfinish in library/ccm.c allows attackers to obtain adjacent CCM context data via invocation of the multipart CCM API with an oversized taglen parameter. This is caused by missing validation of t...

CVE-2026-34876

The CVE-2026-34876 issue affects Mbed TLS 3.x prior to 3.6.6. An out-of-bounds read in mbedtls_ccm_finish() (library/ccm.c) can reveal adjacent CCM context data when the multipart CCM API is invoked with an oversized tag_len. Root cause: missing validation of tag_len against the internal 16-byte ...

Mbed TLS 安全漏洞

Mbed TLS is an open-source, portable, easy-to-use, readable, and flexible SSL library developed by Mbed TLS. Versions of Mbed TLS prior to 3.6.6 contained security vulnerabilities. These vulnerabilities stemmed from a lack of validation for the taglen parameter in the mbedtlsccmfinish function,...

CVE-2026-34876

An issue was discovered in Mbed TLS 3.x before 3.6.6. An out-of-bounds read vulnerability in mbedtlsccmfinish in library/ccm.c allows attackers to obtain adjacent CCM context data via invocation of the multipart CCM API with an oversized taglen parameter. This is caused by missing validation of t...