Heap-based buffer overflow in the multipart form-data parser in jst_post.c in RDK-B WebUI rdkb-2025q4-kirkstone.04.10.26 allows a remote… (CVE-2026-19508)

CVE-2026-19508 is a critical heap-based buffer overflow vulnerability in the multipart form-data parser within jst_post.c of the RDK-B WebUI rdkb-2025q4-kirkstone.04.10.26. An unauthenticated remote attacker can exploit this vulnerability by crafting a malicious multipart/form-data HTTP request, leading to memory corruption. The impact includes denial of service and the potential for arbitrary code execution. The vulnerability is classified under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer). No patch or remediation information is currently provided, and no known exploits are reported in the wild.

Successful exploitation can lead to memory corruption resulting in denial of service or arbitrary code execution by a remote unauthenticated attacker. The CVSS v3.1 score is 9.8 (critical), reflecting high confidentiality, integrity, and availability impacts with no required privileges or user interaction.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, consider restricting access to the vulnerable WebUI component and monitoring for suspicious multipart/form-data requests. No official fix or workaround has been documented at this time.