CVE-2026-38427

HIGH

Tasmota through 15.3.0.3 - Heap Buffer Overflow in fetch_jpg()

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2026-38427. PoCs published by sermikr0.

AI-analyzed exploit summary The repository contains a functional PoC exploit for CVE-2026-38427, demonstrating a uint16_t integer wraparound vulnerability in Tasmota's fetch_jpg() function, leading to heap corruption and potential DoS or RCE.

Description

An issue in fetch_jpg() in xdrv_10_scripter.ino in Tasmota through 15.3.0.3 allows a remote attacker to cause heap buffer overflow. The Content-Length from a JPEG stream is stored in a uint16_t variable; values above 65535 wrap around, causing allocation of a smaller buffer than the data actually read.

Exploits (1)

nomisec WORKING POC
by sermikr0 · poc
https://github.com/sermikr0/CVE-2026-38427

The repository contains a functional PoC exploit for CVE-2026-38427, demonstrating a uint16_t integer wraparound vulnerability in Tasmota's fetch_jpg() function, leading to heap corruption and potential DoS or RCE.

Classification
Working Poc 100%
Attack Type
Dos
Complexity
Moderate
Reliability
Reliable
Target: Tasmota <= 15.3.0.3
No auth needed
Prerequisites: Network access to the target Tasmota device · Ability to make the device connect to an attacker-controlled server
mistral-large-3 · analyzed Jul 02, 2026 Full analysis →

References (2)

Core 2

Scores

CVSS v3 7.3
EPSS 0.0046
EPSS Percentile 37.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact partial

Details

CWE
CWE-122
Status published
Published May 27, 2026
Tracked Since May 27, 2026