CVE-2026-43937

FAUCET Score

YetAnotherForum.NET (YAF.NET) is a C# ASP.NET forum. Prior to 4.0.5, Any admin OnPost… handler executes its side effects before the ResultFilterAttribute rewrites the response to a 302 to /Info/4. The most impactful abuse is /Admin/RunSql, whose OnPostRunQuery binds Editor from the POST body and passes it straight to IDbAccess.RunSql with no caller check, yielding arbitrary SQL execution for any low-privileged user. This vulnerability is fixed in 4.0.5.

First published: May 12, 2026Last modified: May 12, 2026

Impacted Technologies

Vendor	Product	Version(s)	CPE
YAFNET	YAFNET	< 4.0.5CNA affected

CVSS Data

CVSS version used by this source: 3.1

8.8HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

Exploitability Score

2.8

Impact Score

5.9

CvssVersion

3.1

Exploit Intelligence

EPSS Score

0.49%

Probability of exploitation in next 30 days

EPSS Percentile

39.2%

Percentile rank of EPSS score among Peer Group

As of 2026-07-27

Model: v2026.06.15

This CVE's current EPSS score of 0.0049 is in the 28th percentile among its peer group of 17,829 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.3 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (1)

nugetpatch availablevia ghsa

Product: YAFNET.CoreFixed in: 4.0.5

Vendor Advisories (1)

nugetGHSA-xhw7-j96h-c3g5high

YAFNET: Pre-Handler Authorization Bypass on Admin Pages Enables Blind SQL Execution via `/Admin/RunSql`

May 5, 2026

References

github.com / YAFNET/YAFNET/security/advisories/GHSA-xhw7-j96h-c3g5