CVE-2026-107891: musl libc: multiple integer overflow in regcomp, possibly leading to incorrect allocation sizes and out-of-bounds heap writes

25 points by dzwdz

andrewrk

TIL libc has regular expressions

fanf

POSIX has both kinds ~~of music, country and western~~ of regex, BRE and ERE.
koreth

They've been in libc (or at least some implementations of libc) since the 1980s, I believe.

libc is always full of surprises, but usually they're not good surprises like this one.
tomjakubowski

Regexes are in the POSIX part of a POSIX-compatible ISO libc.

dzwdz

thanks to @cadey to mentioning this on IRC. there's more detail in the commit message in the linked patch