omniauth-apple allows attacker to fake their email address during authentication

Exploitation

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

CVSS

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

EPSS

• CVE-2020-26254: 1.34% estimated exploitation activity in the next 30 days; percentile 71.30 (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.

Impact This vulnerability impacts applications using the omniauth-apple strategy of OmniAuth and using the info.email field of OmniAuth's Auth Hash Schema for any kind of identification. The value of this field may be set to any value of the attacker's choice including email addresses of other users. For example, an application using omniauth-apple with the following code will be impacted: Applications not using info.email for identification but are instead using the uid field are not impacted in the same manner. Note, these applications may still be negatively affected if the value of info.email is being used for other purposes. Patches Applications using affected versions of omniauth-apple are advised to upgrade to omniauth-apple version 1.0.1 or later. Workarounds If unable to upgrade to a patched version, monkey patching OmniAuth::Strategies::Apple#email as follows is advised as a workaround:

Published by the source

8 Dec 2020, 14:18 UTC

Last modified by the source

6 Nov 2023, 05:00 UTC

Source last checked

26 Oct 2026, 15:48 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-49r3-2549-3633

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# Patch Next advisory brief: CVE-2020-26254

Advisory: omniauth-apple allows attacker to fake their email address during authentication
IDs: CVE-2020-26254, GHSA-49r3-2549-3633
Record: https://patchnext.com/advisories/cve-2020-26254 (revision 1, source checked 26 Oct 2026, 15:48 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: omniauth-apple 1.0.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- RubyGems omniauth-apple: affected < 1.0.1; fixed in 1.0.1

## Suggested inspection (read-only)
- RubyGems omniauth-apple: 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 omniauth-apple.
- 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-49r3-2549-3633 (GitHub-reviewed advisory GHSA-49r3-2549-3633 lists affected ranges: RubyGems omniauth-apple >=0 <1.0.1)

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