CVE-2026-43891

CVE-2026-43891 is a high-severity vulnerability in Webtechnologies Changedetection with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-73.

Key facts

Description

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.

Frequently asked questions

What is CVE-2026-43891?
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.
How severe is CVE-2026-43891?
CVE-2026-43891 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-43891 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-43891?
CVE-2026-43891 affects Webtechnologies Changedetection. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-43891?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-43891 have an EU (EUVD) identifier?
Yes. CVE-2026-43891 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-29720.
When was CVE-2026-43891 published?
CVE-2026-43891 was published on 2026-05-12 and last updated on 2026-06-17.

References

Affected products (1)

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