CVE-2023-37303

Exp

An issue was discovered in the CheckUser extension for MediaWiki through 1.39.3. In certain situations, an attempt to block a user fails after a temporary browser hang and a DBQueryDisconnectedError error message.

Published: 2023-06-30 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-37303 is rated High Exploit Risk (72.8/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 0.80%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2023-37303

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2023-37303

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.19% 0.80% +0.61%
2 2025-11-21 0.30% 0.19% -0.11%
3 2025-11-18 — 0.30% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-37303

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]

Weakness enumeration for CVE-2023-37303

OS Trackers for CVE-2023-37303

vendor priority summary link
ubuntu medium CVE-2023-37303 medium priority: Ubuntu including 1 source packages (mediawiki), 13 status rows across 13 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 7, needs-triage 6. https://ubuntu.com/security/CVE-2023-37303

Affected software / configurations for CVE-2023-37303

Vendor Product Version Raw CPE
mediawiki mediawiki <= 1.39.3 cpe:2.3:a:mediawiki:mediawiki:*:*:*:*:*:*:*:*

References for CVE-2023-37303

cvelogic Threat Intelligence