Security Resilience

CVE-2026-43891

Path Traversal in Webtechnologies Changedetection ≤ 0.55.1

Public PoCPath Traversal
Published
12 May 2026
Modified
17 June 2026
Patch / advisory
View advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS Score 0.0050 41th percentile
Risk Priority 58 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

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 Dynamic Linker Hijacking (T1574.006); ranked at the 41th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and AC-3 (Access Enforcement) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A06:2025 Insecure Design

EU & UK References

Vulnerability Data

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…

more

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 Techniques

T1574.006 Dynamic Linker Hijacking Stealth
Adversaries may execute their own malicious payloads by hijacking environment variables the dynamic linker uses to load shared libraries.
attack.mitre.org →
T1083 File and Directory Discovery Discovery
Adversaries may enumerate files and directories or may search in specific locations of a host or network share for certain information within a file system.
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 →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-41895Same product: Webtechnologies Changedetection
CVE-2026-27645Same product: Webtechnologies Changedetection
CVE-2026-29038Same product: Webtechnologies Changedetection
CVE-2023-24769Same product: Webtechnologies Changedetection
CVE-2026-35000Same product: Webtechnologies Changedetection
CVE-2026-25527Same product: Webtechnologies Changedetection
CVE-2026-29065Same product: Webtechnologies Changedetection
CVE-2026-29039Same product: Webtechnologies Changedetection
CVE-2026-27696Same product: Webtechnologies Changedetection
CVE-2024-23329Same product: Webtechnologies Changedetection

Affected Assets

webtechnologies
changedetection
≤ 0.55.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V5.3.2

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match

Input validation directly rejects or sanitizes untrusted path strings before they reach filesystem operations.

AC-3 Access Enforcement partial match

Enforces authorization checks on the actual resource accessed, blocking unauthorized files even when a malicious path is supplied.

AC-6 Least Privilege partial match

Least-privilege limits the set of files or directories any subject can affect, shrinking the blast radius of a path-control flaw.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 full match
blocks

Secure SDLC practices include input validation and path sanitization that eliminate this weakness.

PR.AA-05 mostly match
blocks

Least-privilege file authorization directly limits damage from externally controlled paths.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect path-traversal issues but does not itself implement preventive controls.

A.8.28 Secure coding partial match
prevents

Secure coding standards require canonicalization, allow-listing, and bounds checks on file paths, directly eliminating CWE-73.

References