RUSTSEC-2026-0414High· 7.5▾ TwilightExponential event growth with `ENABLE_WIKILINKS`
▾ Twilight zone — High severity, or a signal on a lesser flaw
impact 41.3 · likelihood 0 · exploitation 0
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Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via OSV
Last analysed / modified upstream
When Options::ENABLE_WIKILINKS is enabled, a wikilink with a pipe separator
and empty display text, such as [[a|]], leaks its child node's sibling chain
into the content that follows it. Each such link roughly doubles the number of
events the parser yields for the rest of the document, so output grows
exponentially with input size: 16 repetitions of [[a|]] (112 bytes) yield
327,676 events, where the fixed parser yields 65. A document of a few kilobytes
is enough to exhaust memory in a process that collects the events or renders
them to HTML.
Applications that parse untrusted Markdown with ENABLE_WIKILINKS set,
including through Options::all(), are affected. The option is off by default.
Parsing without it is not affected.
The flaw was fixed in #1102 and released in 0.13.5.
pulldown-cmark >= 0.13.0, < 0.13.5Upgrade to a patched release:
pulldown-cmark 0.13.5Connected by shared product, vendor, weakness, or advisory.