CVE-2026-115348: high-severity vulnerability in lepture mistune
Mistune before 3.3.0 Quadratic-Time DoS via parse_link_text
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.7epss 0.4%
Mistune from 3.0.0 before 3.3.0 contains an algorithmic complexity vulnerability in the inline link parser's parse_link_text function that allows unauthenticated attackers to exhaust CPU with unbalanced brackets. Attackers can submit Markdown containing many unbalanced '[' or '![' characters, forcing repeated unbounded forward scans and tying up worker processes for minutes.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Affected products
lepture · mistuneRelated CVEs — lepture mistune
In the same product, most dangerous first.
CVE-2026-59928HIGHMistune block_parser: quadratic-time parsing on long lists of repeated reference-link definitionsEPSS 0.7%CVE-2026-59925HIGHinline_parser: quadratic-time parsing on long runs of `**x**` and `***x***` emphasis pairsEPSS 0.6%CVE-2026-59922HIGHMistune plugins/formatting: quadratic-time parsing on long runs of `~~x~~`, `==x==`, and `^^x^^` markers (strikethrough / mark / insert)EPSS 0.6%CVE-2026-121437HIGHMistune 3.3.0 before 3.3.4 Quadratic-Time DoS via _process_emphasis_delimitersEPSS 0.6%CVE-2026-33079HIGHMistune ReDoS in LINK_TITLE_RE allows denial of service with crafted Markdown titlesEPSS 0.6%CVE-2026-59927MEDIUMMistune directives/include: mutual `.. include::` recursion crashes the renderer with `RecursionError`, denial of service via two attacker-controlled markdown filesEPSS 0.5%