1. vuln - Noun
2. vuln - Verb
vuln (third-person singular simple present vulns, present participle vulning, simple past and past participle vulned)
(heraldry, especially of a pelican) To wound (oneself) by biting at the breast.
The shield depicts a pelican vulning herself.
vuln (plural vulns)
(computing, informal) A vulnerability (weakness in software etc. that can be maliciously exploited).