PatchTheCVECVE-2026-49952: Discuz! X5.0 releases 20260320 through 20260501 contains an authentication bypass vulnerability that allows un
CVE-2026-49952 is a critical-severity flaw (CVSS 9.1) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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
Why this priority
- Critical severity
- EPSS top 8%: very likely to be exploited
- Public exploit reference
- CISA SSVC: automatable with total technical impact
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 9.1 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 4.7% (top 8%) |
| CISA exploited list | No |
| Weakness | CWE-323 |
| Published | 2026-06-15 |
| Last modified | 2026-10-25 |
Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Exact fixes by distribution
Public exploits and detection
Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.
- GitHub PoC: passwa11/CVE-2026-49952 (3 stars)
- GitHub PoC: CerberusMrXi/Discuz-X5.0-Authentication-Bypass-Exploit-Framework (1 stars)
- Write-up: karmainsecurity.com/KIS-2026-09
- Write-up: karmainsecurity.com/chaining-bugs-in-discuz-from-race-condition-to-rce
- Exploit-DB: Discuz! X5.0 - Authentication Bypass
- Nuclei scan template: Discuz! X5.0 - Authentication Bypass
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-49952?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-49952 being exploited?
CVE-2026-49952 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-49952 affect?
CVE-2026-49952 affects affected software. Severity is critical (CVSS 9.1). 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 cry
How urgent is CVE-2026-49952?
Priority 68/100. Critical severity; EPSS top 8%: very likely to be exploited; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action