CyberSecBulletin
CVE-2026-81525NVD status: Analyzed

PHP Library: Improper Neutralization of Special Elements in Data Query Logic

Published Updated By the CyberSecBulletin desk

CVE-2026-81525 is a high-severity improper neutralization of special elements in data query logic vulnerability in PHP Library from MongoDB, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists versions 1.21.4, 2.4.1 as the first without the flaw, so updating PHP Library to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.49% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update PHP Library to 1.21.4 or 2.4.1, whichever matches your release line, or a later version.
  2. Update PHP Extension to 1.21.6 or 2.4.1, whichever matches your release line, or a later version.
  3. Update PHP Driver to 1.21.6 or 2.4.1, whichever matches your release line, or a later version.
  4. Read the advisory on jira.mongodb.org for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
MongoDBPHP Librarybefore 1.21.4; 2.0.0 up to, but not including, 2.4.11.21.4, 2.4.1
MongoDBPHP Extensionbefore 1.21.6; 2.0.0 up to, but not including, 2.4.11.21.6, 2.4.1
MongoDBPHP Driverbefore 1.21.6; 2.0.0 up to, but not including, 2.4.11.21.6, 2.4.1

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
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N. Scored by CNA (mongodb.com).

Scoring systemScoreSeverityScored by
CVSS 4.08.6HighCNA (mongodb.com)
CVSS 3.18.1HighCNA (mongodb.com)

Official description

The MongoDB client library for PHP does not sufficiently sanitize special elements in application-supplied namespace identifiers before using them to construct the target namespace for database operations. An application that incorporates untrusted text into these identifiers may have operations silently directed at a different storage location than the one the application intended.

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

The underlying weakness: Improper Neutralization of Special Elements in Data Query Logic

The product generates a query intended to access or manipulate data in a data store such as a database, but it does not neutralize or incorrectly neutralizes special elements that can modify the intended logic of the query.

More Improper Neutralization of Special Elements in Data Query Logic vulnerabilities (CWE-943)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in PHP Library

All PHP Library vulnerabilities

Recent Improper Neutralization of Special Elements in Data Query Logic vulnerabilities

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