Description
Vim is an open source, command line text editor. From 9.1.0011 to before 9.2.0137, Vim's NFA regex compiler, when encountering a collection containing a combining character as the endpoint of a character range (e.g. [0-0\u05bb]), incorrectly emits the composing bytes of that character as separate NFA states. This corrupts the NFA postfix stack, resulting in NFA_START_COLL having a NULL out1 pointer. When nfa_max_width() subsequently traverses the compiled NFA to estimate match width for the look-behind assertion, it dereferences state->out1->out without a NULL check, causing a segmentation fault. This vulnerability is fixed in 9.2.0137.
Problem types
CWE-476: NULL Pointer Dereference
Product status
References
github.com/vim/vim/security/advisories/GHSA-9phh-423r-778r
github.com/...ommit/36d6e87542cf823d833e451e09a90ee429899cec
github.com/vim/vim/releases/tag/v9.2.0137