VulnerabilityPublished 26 Mar 2026

CVE-2026-33672: micromatch picomatch · Prototype Pollution

Affects micromatch picomatchSource CVE Database V5

Compare

Not known to be exploited · CVSS 5.3 Medium · fixed in 4.0.4 : update micromatch picomatch when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.4% chance of exploitation in 30 days – higher than 36% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 4.0.4, 3.0.2, 2.3.2

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 26 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade picomatch to 4.0.4, 3.0.2 or 2.3.2; picomatch to 2.3.2.

Affected software

Product	Affected	Fixed in
micromatchpicomatch	Affected >=4.0.0 <4.0.4	Fixed in 4.0.4
micromatchpicomatch	Affected >=3.0.0 <3.0.2	Fixed in 3.0.2
micromatchpicomatch	Affected <2.3.2	Fixed in 2.3.2
npmpicomatch`pkg:npm/picomatch`Other threats	Affected <2.3.2	Fixed in 2.3.2

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix is available in picomatch versions 4.0.4, 3.0.2, and 2.3.2. Users should upgrade to one of these versions or later according to their supported release line. If upgrading is not immediately possible, avoid passing untrusted glob patterns to picomatch. Additional mitigations include sanitizing or rejecting untrusted glob patterns containing POSIX character classes (e.g., [[:...:]]), avoiding the use of POSIX bracket expressions when user input is involved, or manually patching the library by modifying POSIX_REGEX_SOURCE to use a null prototype. These mitigations reduce the risk of incorrect glob matching behavior caused by this vulnerability.

Description

CVE-2026-33672 is a prototype pollution vulnerability in the JavaScript glob matching library picomatch affecting versions prior to 4.0.4, 3.0.2, and 2.3.2. The vulnerability arises from improper handling of POSIX bracket expressions that can reference inherited Object.prototype methods, leading to incorrect glob matching behavior. This can cause security-relevant logic errors in applications relying on picomatch for filtering, validation, or access control.

Impact

The vulnerability impacts the integrity of glob matching by causing patterns to match unintended filenames. This can lead to security-relevant logic errors in applications that use picomatch for filtering, validation, or access control decisions. There is no impact on confidentiality or availability, and remote code execution is not possible. The issue primarily affects applications processing untrusted or user-controlled glob patterns.

CWE-1321Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution) (opens in a new tab)
Variant weakness
The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.
Implementation
By freezing the object prototype first (for example, Object.freeze(Object.prototype)), modification of the prototype becomes impossible.
Architecture and Design
By blocking modifications of attributes that resolve to object prototype, such as proto or prototype, this weakness can be mitigated.
Implementation · Input Validation
When handling untrusted objects, validating using a schema can be used.
OWASP Cheat Sheets
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V5.1.2 (opens in a new tab)
Attack patterns
Accessing Functionality Not Properly Constrained by ACLs (opens in a new tab)
Exploiting Incorrectly Configured Access Control Security Levels (opens in a new tab)
Manipulating User-Controlled Variables (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 3 Apr 2026, 13:42 UTC

WeaknessesCWE-1321

Technical details

References

Community reviews

Related threats