Mistune from 3.0.0 before 3.3.0 contains an algorithmic complexity denial of service vulnerability in the parse_link_text function in src/mistune/helpers.py. Attackers can submit markdown with deeply nested square brackets triggering quadratic parsing time, exhausting server CPU with small crafted requests.

The remote Fedora 44 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-ea39a303cf advisory.

    Update to 3.3.4


Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Fedora 43 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-340793a2f1 advisory.

    Update to 3.3.4

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Mistune from 3.0.0 before 3.3.0 contains an algorithmic complexity denial of service vulnerability in the     parse_link_text function in src/mistune/helpers.py. Attackers can submit markdown with deeply nested     square brackets triggering quadratic parsing time, exhausting server CPU with small crafted requests.
    (CVE-2026-115349)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
376834	Fedora 44 : python-mistune (2026-ea39a303cf)	Nessus	Fedora Local Security Checks	Local	critical
376819	Fedora 43 : python-mistune (2026-340793a2f1)	Nessus	Fedora Local Security Checks	Local	critical
371261	Linux Distros Unpatched Vulnerability : CVE-2026-115349	Nessus	Misc.	Local	high

Detections

Analytics

CVE-2026-115349

high

Tenable Plugins

critical

critical

high