Submit #836743: Arendst Tasmota 15.3.0.3 Memory Corruptioninfo

TitleArendst Tasmota 15.3.0.3 Memory Corruption
DescriptionA buffer overflow vulnerability exists in Arendst Tasmota firmware version x.x.x.x and prior in the file tasmota/tasmota_xdrv_driver/ xdrv_10_scripter.ino within the fetch_jpg() function (case 0). The vulnerable code copies a server-controlled MJPEG boundary string into a fixed-size 40-byte stack buffer (boundary[40]) using strcpy() without any length validation: strcpy(glob_script_mem.jpg_task.boundary, cp + 1); An attacker who controls the MJPEG HTTP server that the Tasmota device connects to via fetchjp() script command can send a Content-Type header with a boundary string longer than 39 characters. This overflows the boundary[40] buffer and corrupts adjacent heap memory including WiFiClient vtable pointers, potentially leading to remote code execution on ESP32-based devices. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (9.8 Critical) CVE-2026-38422 PoC: https://github.com/sermikr0/CVE-2026-38422
Source⚠️ https://github.com/sermikr0/CVE-2026-38422
User sermikro (UID 98509)
Submission05/25/2026 12:25 (17 days ago)
Moderation06/07/2026 21:58 (13 days later)
StatusDuplicate
VulDB entry366173 [arendst Tasmota up to 15.3.0.3 xdrv_10_scripter.ino fetch_jpg buffer overflow]
Points0

Do you need the next level of professionalism?

Upgrade your account now!