istream.c in w3m 0.5.2 and possibly other versions, when ssl_verify_server is enabled, does not properly handle a '\0' character in a domain name in the (1) subject's Common Name or (2) Subject Alternative Name field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408.

An out-of-bounds read flaw was found in w3m, in the Strnew_size function in Str.c. This issue may allow an attacker to cause a denial of service through a crafted HTML file.

An out-of-bounds read flaw was found in w3m, in the growbuf_to_Str function in indep.c. This issue may allow an attacker to cause a denial of service through a crafted HTML file.

An out-of-bounds write issue has been discovered in the backspace handling of the checkType() function in etc.c within the W3M application. This vulnerability is triggered by supplying a specially crafted HTML file to the w3m binary. Exploitation of this flaw could lead to application crashes, resulting in a denial of service condition.