There is an Open Redirect vulnerability in Gnuboard v6.0.4 and below via the `url` parameter in login path.

gnuboard gnuboard4 v4.36.04 and before is vulnerable to Second-order SQL Injection via the search_table in bbs/search.php.

Cross Site Scripting (XSS) vulnerability in Gnuboard 5.6.15 allows authenticated attackers to execute arbitrary code via crafted c_id parameter in bbs/view_comment.php.

Cross Site Scripting (XSS) vulnerability in Gnuboard g6 before Github commit 58c737a263ac0c523592fd87ff71b9e3c07d7cf5, allows remote attackers execute arbitrary code via the wr_content parameter.

Cross-site Scripting (XSS) - Reflected in gnuboard/gnuboard5

gnuboard5 is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Gnuboard g6 6.0.7 is vulnerable to Session hijacking due to a CORS misconfiguration.