CVE-2026-43891 | changedetection.io: Arbitrary Local File Read via crafted backup restore

Exp

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.

Published: 2026-05-12 Last update: 2026-05-15 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-43891 is rated Exploit Available (50/100): CVSS High severity, with low exploitation likelihood (EPSS 0.03%). Core evidence: 2 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-43891

EDB-ID Source Kind Published Link
nvd_ref exploit_tag Exploit-DB ↗
nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-43891

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-13 0.03%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-43891

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
3.9 3.6 [email protected]

Weakness enumeration for CVE-2026-43891

GitHub Security Advisory for CVE-2026-43891

GHSA-8757-69j2-hx56 · Severity: high · Ecosystem: pip — changedetection.io has an Arbitrary Local File Read via a crafted backup restore

Affected software / configurations for CVE-2026-43891

Vendor Product Version Raw CPE
webtechnologies changedetection < 0.55.1 cpe:2.3:a:webtechnologies:changedetection:*:*:*:*:*:*:*:*

References for CVE-2026-43891

cvelogic Threat Intelligence