CVE-2026-126068

NameCVE-2026-126068
DescriptionAction Mailbox routes incoming emails to controller-like mailboxes for processing in Rails. Prior to 8.1.4.1 and 8.0.5.2, the Action Mailbox Mailgun ingress authenticates a request with an HMAC of the timestamp and token parameters concatenated without a separator, and ActionMailbox::Ingresses::Mailgun::InboundEmailsController::Authenticator#recent? rejects only timestamps more than 2 minutes in the past. Because the signature does not fix the boundary between the two values, a captured signed request can be presented with a timestamp far in the future, which the ingress then accepts indefinitely. An attacker who obtains one signed Mailgun webhook request, but not the signing key, could submit arbitrary inbound email that Action Mailbox processes as genuine, possibly leading to forged messages attributed to the sender of the attacker's choosing. Applications that receive inbound email through the Action Mailbox Mailgun ingress are affected. This issue is fixed in versions 8.1.4.1 and 8.0.5.2.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
rails (PTS)bookworm2:6.1.7.10+dfsg-1~deb12u2vulnerable
bookworm (security)2:6.1.7.10+dfsg-1~deb12u3vulnerable
trixie2:7.2.2.2+dfsg-2~deb13u1vulnerable
trixie (security)2:7.2.2.2+dfsg-2~deb13u2vulnerable
forky2:7.2.4+dfsg-1vulnerable
sid2:7.2.4+dfsg-2vulnerable

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
railssource(unstable)(unfixed)

Notes

https://github.com/rails/rails/security/advisories/GHSA-5957-c7qm-m469

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