CVE-2026-40472 | Hackage package metadata stored XSS vulnerability

In hackage-server, user-controlled metadata from .cabal files are rendered into HTML href attributes without proper sanitization, enabling stored Cross-Site Scripting (XSS) attacks.

Published: 2026-04-23 Last update: 2026-04-24 Assigner: 74b3a70d-cca6-4d34-9789-e83b222ae3be Source: 74b3a70d-cca6-4d34-9789-e83b222ae3be
NVD Status：Awaiting Analysis，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-40472 is rated Moderate Risk (45.2/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.05%). Review affected assets and schedule remediation.

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

Exploit prediction scoring system (EPSS) score for CVE-2026-40472

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 2026-04-29 0.05% 0.05% +0.01%
2 2026-04-24 — 0.05% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-40472

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.9 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L 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:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
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:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.1 6.0 74b3a70d-cca6-4d34-9789-e83b222ae3be

Weakness enumeration for CVE-2026-40472

GitHub Security Advisory for CVE-2026-40472

GHSA-8fw8-47cx-j4q4 · Severity: critical — In hackage-server, user-controlled metadata from .cabal files are rendered into HTML href...

Affected software / configurations for CVE-2026-40472

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-40472

cvelogic Threat Intelligence