Exim End of Life (EOL) Dates & Support Timeline

Exim release and support pattern

Across the 41 release lines with a published release date, Exim has shipped a new line roughly every 5 months (median interval). A line typically stays supported for about 5 months from its release to its end-of-life date (measured on the 40 lines with both dates published).

Of the 41 release lines tracked, 40 are past end of life and 1 is still within support. The newest line, 4.99, was released October 28, 2025. No end-of-life date is currently published for the 1 supported line.

Computed from the tracked release data at every build — the figures above are the dates in the table, restated, not an editorial estimate.

Exim security intelligence

CISA KEV history: Exim is named in CISA's Known Exploited Vulnerabilities catalog 5 times, most recently on 2022-03-25, including use in ransomware campaigns. Derived from CISA's live catalog at every build.

Patch behavior after end of life: Hard cutoff — supported versions only. The KEV-listed CVE-2019-10149 ('Return of the WIZard') was never fixed in Exim 4.91 or earlier — the fix shipped in 4.92 and the project expects mail operators to track current releases. Exim publishes no extended-support mechanism of any kind. (Observed behavior from our primary-source verification sweep, checked 2026-08-07 — never a guarantee of future fixes.)

What does Exim end of life mean for your organization?

When a version of Exim reaches end of life, the maintainers stop issuing security patches. Vulnerabilities discovered after this date are publicly disclosed on the National Vulnerability Database, exploit code appears on GitHub, and your systems remain permanently exposed.

The CVE blind spot: Most vulnerability scanners check for known CVEs but do not flag the accumulation of unpatched vulnerabilities in EOL software. With a zero-day, nobody knows about the vulnerability. With EOL software, the vulnerability is public — listed, rated, and often weaponized — but no patch will ever exist. This is the most dangerous gap in enterprise security posture.

Organizations running EOL Exim should treat it as a vulnerability class in their risk register, apply compensating controls (network segmentation, enhanced monitoring, access restriction), and prioritize migration to a supported version.

Your options when Exim reaches end of life

There are four realistic paths. Which one is right depends far more on how long the system needs to keep running than on the version you are on today.

How to choose, in one question: how many more years does this system need to run? Under a year, extended support (where it exists) is usually cheaper than an emergency migration. One to three years, migrate — support purchased repeatedly costs more than doing the project once, and the project only gets harder as the version ages. Indefinitely, migrate now and plan the next migration before it surprises you.

Worth saying plainly, because vendors selling extended support rarely will: extended support is often the more expensive choice over a multi-year horizon. It is the right answer when a deadline is genuinely unreachable, not as a default. Compare the annual fee against the one-time cost of migrating before committing to either.

Formalizing decisions like this across your estate? Our free EOL policy template is a ready-to-adopt policy with risk tiers, remediation SLAs, and audit mapping — no signup, free to use and share.

Extended Support Options

If you cannot migrate immediately, extended support vendors provide continued security patches for EOL Exim versions. This is a bridge, not a permanent solution — plan your migration in parallel.

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