Public proof of concept

CVE-2026-49952

A public proof of concept exists; no exploitation attested.

Published2026-06-15
WeaknessCWE-323

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC

2026-06-1520:16CVE publishedNVD
2026-10-2319:23First public proof of conceptPoC-in-GitHub

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-49952?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-49952?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

Neither OSV.dev nor the vendor advisories we read list affected versions for CVE-2026-49952 yet.

Full record on NVD

Fix

No fix published by the sources we read yet. NVD record

Detection

read 2026-10-23 19:25 UTC

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: 2 repositories, unverifiedpasswa11/CVE-2026-49952CerberusMrXi/Discuz-X5.0-Authentication-Bypass-Exploit-Framework

Sources

NVDCVE recordread 2026-10-23
CISA-ADPSSVC decisionpoc2026-06-15
OpenCVESSVC decisionpoc—
CNACVSS 4.09.3read 2026-10-23
CNACVSS 3.19.1read 2026-10-23
CNAweakness (CWE)CWE-323read 2026-10-23
FIRST EPSSEPSS score3.7 %2026-10-23
PoC-in-GitHubproof of concept2read 2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CVSS 4.0 vector: 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
Published: 2026-06-15
Last Modified: 2026-06-17
NVD status: Deferred

Frequently asked questions

What is CVE-2026-49952?

Is CVE-2026-49952 actively exploited?

A proof-of-concept exploit exists for CVE-2026-49952, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2026-49952?

CVE-2026-49952 has a CVSS v3 base score of 9.1 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

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