CVE-2026-49952: Discuz! X5.0 Authentication Bypass via dbbak.php Encryption Oracle
Discuz! · Discuz! X5.0
Vendor fix available · Affected: Discuz! X5.0 · Exploitation: check available, not yet exploited
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 91% of scored CVEs
DescriptionCVE.org
Discuz! X5.0 releases 20260320 through 20260501 contains an authentication bypass vulnerability that allows unauthenticated remote attackers to gain unauthorized access to database backup and restore functionality by exploiting a shared cryptographic key between UCenter integration and the database backup API exposed by dbbak.php. Attackers can inject a crafted payload through the username parameter during login to abuse the encryption oracle in logging_ctl::logging_more(), obtain a legitimately signed token, and use it to bypass authorization for database export and import operations, with the additional ability to trigger a race condition to impersonate arbitrary users.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- Discuz! · Discuz! X5.0from 20260320 up to and including 20260501
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Check available, not yet exploited. A public nuclei template can confirm it on a system you are authorised to test.
- CISA KEV
- Not listed
- Public check
- Discuz! X5.0 - Authentication Bypass · nuclei template in projectdiscovery/nuclei-templates
- Vendor
- Discuz!
- Published
- June 2026
CoverageNo articles yet
No CyberSIXT article names CVE-2026-49952 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.