CVE-2026-4539

Severity CVSS v4.0:

MEDIUM

Type:

CWE-400 Uncontrolled Resource Consumption ('Resource Exhaustion')

Publication date:

22/03/2026

Last modified:

23/03/2026

Description

A security flaw has been discovered in pygments up to 2.19.2. The impacted element is the function AdlLexer of the file pygments/lexers/archetype.py. The manipulation results in inefficient regular expression complexity. The attack is only possible with local access. The exploit has been released to the public and may be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.

Impact

Vector 4.0

CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P CVSS v4.0 Severity and Metrics:

Base Score: 4.80 MEDIUM
Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P

Attack Vector (AV): Local
Attack Complexity (AC): Low
Attack Requirements (AT): None
Privileges Required (PR): Low
User Interaction (UI): None
Confidentiality (VC): None
Integrity (VI): None
Availability (VA): Low
Confidentiality (SC): None
Integrity (SI): None
Availability (SA): None
Exploit Maturity (E): POC

Base Score 4.0

4.80

Severity 4.0

MEDIUM

Vector 3.x

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L CVSS v3.1 Severity and Metrics:

Base Score: 3.30 LOW
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): None
Availability (A): Low

Base Score 3.x

3.30

Severity 3.x

LOW

Vector 2.0

AV:L/AC:L/Au:S/C:N/I:N/A:P CVSS v2.0 Severity and Metrics:

Base Score: 1.70 LOW
Vector: AV:L/AC:L/Au:S/C:N/I:N/A:P

Attack Vector (AV): Local
Attack Complexity (AC): Low
Authentication (Au): Single
Confidentiality (C): None
Integrity (I): None
Availability (A): Physical

Base Score 2.0

1.70

Severity 2.0

LOW

CVE-2026-4539

Description

Impact

References to Advisories, Solutions, and Tools