CyberSecBulletin
CVE-2026-101148NVD status: Deferred

BackupSheep WordPress Backup Plugin: External Control of File Name or Path

Published Updated By the CyberSecBulletin desk

CVE-2026-101148 is a critical-severity external control of file name or path vulnerability in BackupSheep WordPress Backup Plugin, with a CVSS 3.1 base score of 10.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected BackupSheep WordPress Backup Plugin versions: 1.8 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.31% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of BackupSheep WordPress Backup Plugin you run against the affected versions below, and install the vendor's latest release.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
BackupSheep WordPress Backup PluginBackupSheep WordPress Backup Plugin1.8 and earlierNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H. Scored by CISA (ADP).

Official description

The BackupSheep WordPress Backup Plugin WordPress plugin through 1.8 does not properly validate its integration key, treating an unset or blank key as valid, which allows unauthenticated attackers to create and download full site backups, including the database with user password hashes, and to delete arbitrary files on the server, leading to sensitive data disclosure and site takeover. The BackupSheep WordPress Backup Plugin WordPress plugin through 1.8 has been closed on WordPress.org since July 2024 and no fixed version is available. Remove it from any site where it is installed.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: External Control of File Name or Path

The product allows user input to control or influence paths or file names that are used in filesystem operations.

How developers prevent this class of flaw

  • When the set of filenames is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames, and reject all other inputs. For example, ID 1 could map to inbox.txt and ID 2 could map to profile.txt. Features such as the ESAPI AccessReferenceMap provide this capability.
  • Run your code in a jail or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict all access to files within a particular directory. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

More External Control of File Name or Path vulnerabilities (CWE-73)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).

References

Recent External Control of File Name or Path vulnerabilities

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