CVEvulnerability
CVE-2026-49952
9.3 CRITICAL
Official page ↗
- Status
- Deferred
- Published
- 2026-06-15
- Last modified
- 2026-10-25
- Assigner
- [email protected]
- CVSS 4.0 ([email protected])
- 9.3 CRITICAL — CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/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
- CVSS 3.1 ([email protected])
- 9.1 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- Weaknesses
- CWE-323
Description
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.
Related
Weakness · CWE (1)
- CWE-323 Reusing a Nonce, Key Pair in Encryption weakness
References
- https://gitee.com/Discuz/DiscuzX/commit/9962dad52c4c6999dabaf91ecd70377c680ff3c6 gitee.com
- https://karmainsecurity.com/KIS-2026-09 karmainsecurity.com
- https://karmainsecurity.com/chaining-bugs-in-discuz-from-race-condition-to-rce karmainsecurity.com
- https://www.vulncheck.com/advisories/discuz-x5-0-authentication-bypass-via-dbbak-php-encryption-oracle www.vulncheck.com
- http://seclists.org/fulldisclosure/2026/Jun/3 seclists.org