CVE-2026-4539Low· 3.3▾ SunlitPygments has Regular Expression Denial of Service (ReDoS) due to Inefficient Regex for GUID Matching
▾ Sunlit zone — Low / medium · no exploitation signal
impact 18.2 · likelihood 0 · exploitation 0
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Exploit-prediction probability, daily snapshots since Jul 13.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via OSV
0.2%
Last analysed / modified upstream
A security flaw has been discovered in pygments before 2.20.0. 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.
pygments < 2.20.0Upgrade to a patched release:
pygments 2.20.0