CVE-2026-43891

HighPublic PoC

Published: 12 May 2026

Published

12 May 2026

Modified

15 May 2026

KEV Added

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Patch

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CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS Score 0.0004 11.5th percentile

Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-43891 is a high-severity External Control of File Name or Path (CWE-73) vulnerability in Webtechnologies Changedetection. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Data from Local System (T1005); ranked at the 11.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

🇪🇺 ENISA EUVD: EUVD-2026-29720

Vulnerability details

changedetection.io is a free open source web page change detection tool. Prior to 0.55.1, the vulnerability is caused by trusting attacker-controlled snapshot paths restored from backup files. The vulnerable flow starts in the backup restore logic. When a backup ZIP…

is restored, the application extracts the archive and copies each restored watch UUID directory directly into the live datastore using shutil.copytree(entry.path, dst_dir). This preserves attacker-controlled files inside the restored watch directory, including history.txt. After restore, the application parses history.txt in the watch history property and returns the contents of the targeted local file. This vulnerability is fixed in 0.55.1.

CWE(s): CWE-73

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1005 Data from Local System Collection

Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.

attack.mitre.org →

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

Why these techniques?

Arbitrary local file read via malicious backup restore in public-facing web app directly enables data collection from local system and exploitation of the exposed application.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v18.1