CVE-2026-23923
CVE-2026-23923 is a medium-severity vulnerability with a CVSS 4.0 base score of 6.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-470.
Key facts
- Severity: Medium (CVSS 4.0 base score 6.9)
- EPSS exploit prediction: 0% (20th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-14956
- Weakness: CWE-470
- Published:
- Last modified:
Description
An unauthenticated attacker can exploit the Frontend 'validate' action to blindly instantiate arbitrary PHP classes. The impact depends on environment setup but appears limited at this time.
Frequently asked questions
- What is CVE-2026-23923?
- An unauthenticated attacker can exploit the Frontend 'validate' action to blindly instantiate arbitrary PHP classes. The impact depends on environment setup but appears limited at this time.
- How severe is CVE-2026-23923?
- CVE-2026-23923 has a CVSS 4.0 base score of 6.9, rated medium severity.
- Is CVE-2026-23923 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-23923?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2026-23923 have an EU (EUVD) identifier?
- Yes. CVE-2026-23923 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-14956.
- When was CVE-2026-23923 published?
- CVE-2026-23923 was published on 2026-03-24 and last updated on 2026-06-17.
References
Other CWE-470 (Unsafe Reflection) vulnerabilities
- CVE-2026-42027 — Critical (CVSS 9.8): Arbitrary Class Instantiation via Model Manifest in Apache OpenNLP ExtensionLoader Versions Affected: before…
- CVE-2025-34393 — Critical (CVSS 9.8): Barracuda Service Center, as implemented in the RMM solution, in versions prior to 2025.1.1, does not correctly verify…
- CVE-2025-53693 — Critical (CVSS 9.8): Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection') vulnerability in Sitecore Sitecore…
- CVE-2023-6943 — Critical (CVSS 9.8): Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection') vulnerability in Mitsubishi Electric…
- CVE-2021-31522 — Critical (CVSS 9.8): Kylin can receive user input and load any class through Class.forName(...). This issue affects Apache Kylin 2 version…
- CVE-2019-1003041 — Critical (CVSS 9.8): A sandbox bypass vulnerability in Jenkins Pipeline: Groovy Plugin 2.64 and earlier allows attackers to invoke arbitrary…