Submit #836744: 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 tasmota/tasmota_xdrv_driver/ xdrv_10_scripter.ino within the fetch_jpg() function. The uint16_t variable 'size' receives Content-Length value via atoi() without range validation. Values exceeding 65535 silently wrap around due to integer truncation: uint16_t size = atoi(cp + 1); // 65537 becomes 1 uint8_t *buff = special_malloc(size); // malloc(1) stream.readBytes(buff, size); // reads only 1 byte A remote attacker controlling the MJPEG server causes undersized heap allocation followed by stream state corruption, leading to heap overflow, crash, or potential 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-2026-38426 PoC: https://github.com/sermikr0/CVE-2026-38426
Source⚠️ https://github.com/sermikr0/CVE-2026-38426
User sermikro (UID 98509)
Submission05/25/2026 12:26 (17 days ago)
Moderation06/07/2026 21:58 (13 days later)
StatusDuplicate
VulDB entry366174 [arendst Tasmota up to 15.3.0.3 xdrv_10_scripter.ino fetch_jpg buffer overflow]
Points0

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