diff -up vim80/src/regexp.c.cve1154 vim80/src/regexp.c
--- vim80/src/regexp.c.cve1154 2022-04-09 12:01:30.054452927 +0200
+++ vim80/src/regexp.c 2022-04-09 12:02:48.987999877 +0200
@@ -4415,8 +4415,17 @@ regmatch(
int mark = OPERAND(scan)[0];
int cmp = OPERAND(scan)[1];
pos_T *pos;
+ size_t col = REG_MULTI ? reginput - regline : 0;
pos = getmark_buf(rex.reg_buf, mark, FALSE);
+
+ // Line may have been freed, get it again.
+ if (REG_MULTI)
+ {
+ regline = reg_getline(reglnum);
+ reginput = regline + col;
+ }
if (pos == NULL /* mark doesn't exist */
|| pos->lnum <= 0 /* mark isn't set in reg_buf */
|| (pos->lnum == reglnum + rex.reg_firstlnum
diff -up vim80/src/testdir/test_regexp_latin.vim.cve1154 vim80/src/testdir/test_regexp_latin.vim