CVE-2026-86433: commonmark 1.5.0 before 2.8.4 Denial of Service via Attributes
thephpleague · commonmark
Fixed in 2.8.4 · Affected: thephpleague commonmark before 2.8.4 · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 44% of scored CVEs
DescriptionCVE.org
commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Attributes extension where AttributesListener::findTargetAndDirection() performs quadratic-time sibling list scanning. Unauthenticated attackers can submit approximately 32 KB of repeated attribute blocks to cause parsing to take over 5 seconds, exhausting server resources.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- thephpleague · commonmarkfrom 1.5.0 before 2.8.4
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Unlikely (under 1%). EPSS under 1%, or no score yet.
- CISA KEV
- Not listed
- Public check
- No public nuclei template
- Vendor
- thephpleague
- Published
- September 2026
CoverageNo articles yet
No CyberSIXT article names CVE-2026-86433 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.