CVE-2026-32700: Devise is an authentication solution for Rails based on Warden. Prior to version 5.0.3, a race condition in Devise's Confirmable module allows an atta...

Description

Devise is an authentication solution for Rails based on Warden. Prior to version 5.0.3, a race condition in Devise's Confirmable module allows an attacker to confirm an email address they do not own. This affects any Devise application using the `reconfirmable` option (the default when using Confirmable with email changes). By sending two concurrent email change requests, an attacker can desynchronize the `confirmation_token` and `unconfirmed_email` fields. The confirmation token is sent to an email the attacker controls, but the `unconfirmed_email` in the database points to a victim's email address. When the attacker uses the token, the victim's email is confirmed on the attacker's account. This is patched in Devise v5.0.3. Users should upgrade as soon as possible. As a workaround, applications can override a specific method from Devise models to force `unconfirmed_email` to be persisted when unchanged. Note that Mongoid does not seem to respect that `will_change!` should force the attribute to be persisted, even if it did not really change, so the user might have to implement a workaround similar to Devise by setting `changed_attributes["unconfirmed_email"] = nil` as well.

Metrics

CVSS 3.1

5.3/10

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

CVSS 4.0

6/10

CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.27%

19.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-362

Affected Software

Vendor	Product	Versions
Heartcombo	Devise	< 5.0.3

References

https://github.com/heartcombo/devise/issues/5783Issue Tracking
https://github.com/heartcombo/devise/pull/5784Issue Tracking, Patch
https://github.com/heartcombo/devise/security/advisories/GHSA-57hq-95w6-v4fcVendor Advisory
https://github.com/rubysec/ruby-advisory-db/blob/master/gems/devise/GHSA-57hq-95w6-v4fc.ymlBroken Link
https://github.com/heartcombo/devise/issues/5783Issue Tracking

Timeline

Published: Mar 18, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-32700?

Devise is an authentication solution for Rails based on Warden. Prior to version 5.0.3, a race condition in Devise's Confirmable module allows an attacker to confirm an email address they do not own. This affects any Devise application using the `reconfirmable` option (the default when using Confirmable with email changes). By sending two concurrent email change requests, an attacker can desynchronize the `confirmation_token` and `unconfirmed_email` fields. The confirmation token is sent to an email the attacker controls, but the `unconfirmed_email` in the database points to a victim's email address. When the attacker uses the token, the victim's email is confirmed on the attacker's account. This is patched in Devise v5.0.3. Users should upgrade as soon as possible. As a workaround, applications can override a specific method from Devise models to force `unconfirmed_email` to be persisted when unchanged. Note that Mongoid does not seem to respect that `will_change!` should force the attribute to be persisted, even if it did not really change, so the user might have to implement a workaround similar to Devise by setting `changed_attributes["unconfirmed_email"] = nil` as well.

How severe is CVE-2026-32700?

CVE-2026-32700 has a CVSS score of 6/10 (MEDIUM severity). The EPSS model estimates a 0.27% probability of exploitation in the next 30 days.

How do I fix CVE-2026-32700?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.