It says coordinated distro release today, and I've received a notice earlier today but that does not include the CVE number. That's confusing / does not seem very coordinated to release 2 separate security update notices in a day.
That mentions 4.98.2-1+deb13u2, and its changelog has:
exim4 (4.98.2-1+deb13u2) trixie-security; urgency=high
* Backport fix for Use-After-Free in GnuTLS BDAT/CHUNKING code path.
This is Exim-Security-2026-05-01.1, fixed upstream in 4.99.3.
-- Andreas Metzler <ametzler@debian.org> Mon, 11 May 2026 19:14:46 +0200
Not ideal, but at least we got the fix.