CVE-2026-115348 Mistune before 3.3.0 Quadratic-Time DoS via parse_link_text
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-115348?
CVE-2026-115348 is a high-severity vulnerability in lepture mistune, published on 22 Oct 2026.
Official description
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.
Weakness: CWE-400
Which versions are affected by CVE-2026-115348?
How do I fix CVE-2026-115348?
No fix has been published for CVE-2026-115348 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-115348 being exploited?
There is no known exploitation of CVE-2026-115348 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-115348, GHSA-h98w-84rc-h77q, GHSA-x2gr-6qf2-fc9x, UBUNTU-CVE-2026-115348.