CVE-2018-6196

w3m through 0.5.3 is prone to an infinite recursion flaw in HTMLlineproc0 because the feed_table_block_tag function in table.c does not prevent a negative indent value.

CVE-2018-6197

w3m through 0.5.3 is prone to a NULL pointer dereference flaw in formUpdateBuffer in form.c.

CVE-2022-38223

There is an out-of-bounds write in checkType located in etc.c in w3m 0.5.3. It can be triggered by sending a crafted HTML file to the w3m binary. It allows an attacker to cause Denial of Service or possibly have unspecified other impact.