CVE-2018-18385

Severity: high (CVSS 7.5 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2018-10-16 · updated 2026-06-17
Weakness: CWE-835

Description

Asciidoctor in versions < 1.5.8 allows remote attackers to cause a denial of service (infinite loop). The loop was caused by the fact that Parser.next_block was not exhausting all the lines in the reader as the while loop expected it would. This was happening because the regular expression that detects any list was not agreeing with the regular expression that detects a specific list type. So the line kept getting pushed back onto the reader, hence causing the loop.

Affected products

Asciidoctor: before 1.5.8 — fixed in 1.5.8

How to fix

Upgrade to a fixed version: Asciidoctor 1.5.8. Check the vendor advisory for mitigations.

References

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