CVE-2026-42509 | Apache Wicket: crafted strings can break out of the JavaScript sequence

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Apache Wicket. This issue affects Apache Wicket: from 8.0.0 through 8.17.0, 9.0.0, from 10.0.0 through 10.8.0. Users are recommended to upgrade to version 10.9.0, which fixes the issue.

Published: 2026-05-06 Last update: 2026-05-07 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-42509 is rated Low Risk (37.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.17%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2026-42509

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 2026-05-07 0.03% 0.17% +0.14%
2 2026-05-06 0.03%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-42509

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N 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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 2.7 [email protected]
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N 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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 2.7 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-42509

GitHub Security Advisory for CVE-2026-42509

GHSA-5x9h-93gp-chpj · Severity: medium · Ecosystem: maven — Apache Wicket has a Cross-site Scripting issue

Affected software / configurations for CVE-2026-42509

Vendor Product Version Raw CPE
apache wicket >= 8.0.0, <= 8.17.0 cpe:2.3:a:apache:wicket:*:*:*:*:*:*:*:*
apache wicket >= 9.0.0, <= 9.22.0 cpe:2.3:a:apache:wicket:*:*:*:*:*:*:*:*
apache wicket >= 10.0.0, < 10.9.0 cpe:2.3:a:apache:wicket:*:*:*:*:*:*:*:*

References for CVE-2026-42509

cvelogic Threat Intelligence