X.509 Email Address Variable Length Buffer Overflow

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2022-3786: 92.49% estimated exploitation activity in the next 30 days; percentile 99.83 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

A buffer overrun can be triggered in X.509 certificate verification, specifically in name constraint checking. Note that this occurs after certificate chain signature verification and requires either a CA to have signed a malicious certificate or for an application to continue certificate verification despite failure to construct a path to a trusted issuer. An attacker can craft a malicious email address in a certificate to overflow an arbitrary number of bytes containing the . character (decimal 46) on the stack. This buffer overflow could result in a crash (causing a denial of service). In a TLS client, this can be triggered by connecting to a malicious server. In a TLS server, this can be triggered if the server requests client authentication and a malicious client connects.

Published by the source

1 Nov 2022, 17:45 UTC

Last modified by the source

2 Feb 2023, 05:04 UTC

Source last checked

26 Oct 2026, 15:33 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-h8jm-2x53-xhp5

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# Patch Next advisory brief: CVE-2022-3786

Advisory: X.509 Email Address Variable Length Buffer Overflow
IDs: CVE-2022-3786, GHSA-h8jm-2x53-xhp5
Record: https://patchnext.com/advisories/cve-2022-3786 (revision 1, source checked 26 Oct 2026, 15:33 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: openssl-src 300.0.11. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io openssl-src: affected >= 300.0.0, < 300.0.11; fixed in 300.0.11

## Suggested inspection (read-only)
- crates.io openssl-src: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on openssl-src.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-h8jm-2x53-xhp5 (GitHub-reviewed advisory GHSA-h8jm-2x53-xhp5 lists affected ranges: crates.io openssl-src >=300.0.0 <300.0.11)

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