CVE-2026-4539

low

Published 2026-03-22 · Modified 2026-04-29

💬 Discuss on Community ✚ Propose mitigation

CVSS v3

3.3

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

CVSS v4 NEW

1.9

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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

VIR risk

3.3

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.

Predictions

Exploit likelihood

34%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

OS impact

Debian Affected 5 releases

Version	Status	Fixed in
trixie	Affected	—
sid	Affected	—
forky	Affected	—
bullseye	Affected	—
bookworm	Affected	—

SUSE Affected 1 release

Version	Status	Fixed in
—	Affected	—

Package impact

Ecosystem	Package	Vulnerable	Fixed
PyPI	pygments	`<2.20.0`	`2.20.0`

References

CWEs

CWE-400 CWE-1333

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.