The table extension in GitHub Flavored Markdown before version 0.29.0.gfm.1 takes O(n * n) time to parse certain inputs. An attacker could craft a markdown table which would take an unreasonably long time to process, causing a denial of service. This issue does not affect the upstream cmark project.
Created ghc-cmark-gfm tracking bugs for this issue:
Affects: fedora-all [bug 1854329]
This issue has been addressed in the following products:
Red Hat Enterprise Linux 8
Via RHSA-2021:1972 https://access.redhat.com/errata/RHSA-2021:1972
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):