CVE-2026-18216: Backup Migration < 2.1.7 - Admin+ Privilege Escalation via Post-Restore Auto-Login
Vulnerability summary
CVE-2026-18216 is a medium (CVSS 6.5) Improper Authentication vulnerability in unknown backup migration. EPSS estimates a 0.51% chance of exploitation in the next 30 days, higher than 42.2% of scored vulnerabilities. 1 public exploit is recorded. Fixed in 2.1.7.
Timeline
- 15-08-2026PublishedVulnerability first disclosed.
- 17-08-2026Last modifiedVulnerability information updated.
Description
The Backup Migration WordPress plugin before 2.1.7 does not properly restrict a post-restore automatic login mechanism, allowing a user who administers one site of a multisite network to obtain a long-lived authenticated session as an administrator of another site in the same network, without credentials and bypassing two-factor authentication.
CVSS metrics
3 scores · 3 sources · 1 version- NVDNIST6.5MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
- wordfenceSource4.7MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:LDiffers
EPSS trend
Probability
0.51%
Chance of exploitation in the next 30 days
Percentile
42%
Versus all other CVEs
30-day change
Increase +0.22 pp
From 0.29% on 22-09-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
1 foundExploit Reference (wpscan.com)
Maturity: unknown
Weaknesses
CWE · root cause- CWE-287Improper AuthenticationWhen an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
- CWE-269Improper Privilege ManagementThe product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.
Affected systems
Unknown1 product
- backup migration< 2.1.7
Wordpress1 product
- backup-backup≤ 2.1.6 (fixed in 2.1.7)
2 vendors · 2 products