CVE-2026-4853 | JetBackup <= 3.1.19.8 - Authenticated (Administrator+) Arbitrary Directory Deletion via Path Traversal in 'fileName' Parameter

The JetBackup – Backup, Restore & Migrate plugin for WordPress is vulnerable to Path Traversal leading to Arbitrary Directory Deletion in versions up to and including 3.1.19.8. This is due to insufficient input validation on the fileName parameter in the file upload handler. The plugin sanitizes the fileName parameter using sanitize_text_field(), which removes HTML tags but does not prevent path traversal sequences like '../'. The unsanitized filename is then directly concatenated in Upload::getFileLocation() without using basename() or validating the resolved path stays within the intended directory. When an invalid file is uploaded, the cleanup logic calls dirname() on the traversed path and passes it to Util::rm(), which recursively deletes the entire resolved directory. This makes it possible for authenticated attackers with administrator-level access to traverse outside the intended upload directory and trigger deletion of critical WordPress directories such as wp-content/plugins, effectively disabling all installed plugins and causing severe site disruption.

Published: 2026-04-17 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-4853 is rated Low Risk (37.3/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.71%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

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

Exploit prediction scoring system (EPSS) score for CVE-2026-4853

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 2026-06-15 0.02% 0.71% +0.69%
2 2026-04-17 0.02%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-4853

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/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:H)
They need powerful rights—admin, root, or similar—before this pays off.
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.
1.2 3.6 [email protected]

Weakness enumeration for CVE-2026-4853

GitHub Security Advisory for CVE-2026-4853

GHSA-8cfg-qq42-h3w8 · Severity: medium — The JetBackup – Backup, Restore & Migrate plugin for WordPress is vulnerable to Path Traversal...

Affected software / configurations for CVE-2026-4853

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-4853

URL Tags
https://plugins.trac.wordpress.org/browser/backup/tags/3.1.17.5/src/JetBackup/Ajax/Calls/AddToQueue.php#L244
https://plugins.trac.wordpress.org/browser/backup/tags/3.1.17.5/src/JetBackup/Ajax/Calls/AddToQueue.php#L64
https://plugins.trac.wordpress.org/browser/backup/tags/3.1.17.5/src/JetBackup/Upload/Upload.php#L66
https://plugins.trac.wordpress.org/browser/backup/trunk/src/JetBackup/Ajax/Calls/AddToQueue.php#L244
https://plugins.trac.wordpress.org/browser/backup/trunk/src/JetBackup/Ajax/Calls/AddToQueue.php#L64
https://plugins.trac.wordpress.org/browser/backup/trunk/src/JetBackup/Upload/Upload.php#L66
https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3495633%40backup&new=3495633%40backup&sfp_email=&sfph_mail=
https://www.wordfence.com/threat-intel/vulnerabilities/id/4aa0fa80-05dd-4fe1-b7b5-7ed0cf13053c?source=cve
cvelogic Threat Intelligence