CVE-2026-102631: authd: Account takeover via username fallback in identity matching after IdP email reassignment
Canonical · authd
Fixed in 0.7.1 · Affected: Canonical authd before 0.7.1 · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 1% of scored CVEs
DescriptionCVE.org
In authd before 0.7.1, the user identity matching in UpdateUser (internal/users/manager.go) resolves an incoming login by the broker-scoped provider ID, but falls back to matching the username when the provider ID does not belong to any known user, and does not reject a conflicting non-empty provider ID. If an identity provider reassigns an email address, which authd uses as the username, to a new account, the new account inherits the previous user's local UID and home directory on its next login. This allows the new user to access and modify files belonging to the previous user, including credentials such as SSH keys and cloud API tokens, and silently rebinds the local account record to the new identity. As a mitigation, administrators should lock or delete the previous user's local authd account when the corresponding IdP account is removed.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- Canonical · authdfrom 0.1 before 0.7.1; from 0.1 before 0.7.1~ubuntu24.04.1; from 0.1 before 0.7.1~ubuntu26.04
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Unlikely (under 1%). EPSS under 1%, or no score yet.
- CISA KEV
- Not listed
- Public check
- No public nuclei template
- Vendor
- Canonical
- Published
- October 2026
CoverageNo articles yet
No CyberSIXT article names CVE-2026-102631 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.