CVE-2023-4853: Red Hat Openshift Serverless 1 on RHEL 8 · Improper Neutralization of Input Leaders
Affects Red Hat Openshift Serverless 1 on RHEL 8Source CVE Database V5
Not known to be exploited · CVSS 8.1 High.
Data as of 26 Oct 2026, 06:26 UTC
- EPSS
- 1.4% chance of exploitation in 30 days – higher than 73% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 20 Sep 2023
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.
What to do
AI-suggested
To mitigate CVE-2023-4853, European organizations should immediately apply any available patches or updates from Red Hat for Openshift Serverless and Quarkus components. In the absence of patches, implement strict input validation and sanitization at the application and API gateway layers to block malicious character permutations. Employ network segmentation and zero-trust principles to limit exposure of sensitive endpoints. Enable detailed logging and monitoring of HTTP requests to detect anomalous patterns indicative of exploitation attempts. Use Web Application Firewalls (WAFs) with custom rules targeting the specific input patterns that bypass security policies. Conduct thorough security testing, including fuzzing and penetration testing, focused on HTTP request handling. Educate developers and DevOps teams about secure coding practices related to input handling in Quarkus and Openshift environments. Finally, maintain an incident response plan tailored to potential exploitation scenarios involving unauthorized access and denial of service.
Description
CVE-2023-4853 is a high-severity vulnerability in Red Hat Openshift Serverless 1 on RHEL 8 caused by improper input sanitization in Quarkus HTTP security policies. The flaw allows certain character permutations in requests to bypass security policy checks, potentially granting unauthorized access to protected endpoints and enabling denial of service. Exploitation requires no authentication or user interaction but has a high attack complexity. The vulnerability impacts confidentiality, integrity, and availability of affected systems. No known exploits are currently reported in the wild. European organizations using Openshift Serverless on RHEL 8 should prioritize patching and implement strict input validation and network segmentation to mitigate risk. Countries with significant Red Hat and Openshift adoption, such as Germany, France, and the UK, are most likely to be affected.
References
- access.redhat.com/errata/RHSA-2023:5170 (opens in a new tab)
- access.redhat.com/errata/RHSA-2023:5310 (opens in a new tab)
- access.redhat.com/errata/RHSA-2023:5337 (opens in a new tab)
- access.redhat.com/errata/RHSA-2023:5446 (opens in a new tab)
- access.redhat.com/errata/RHSA-2023:5479 (opens in a new tab)
- access.redhat.com/errata/RHSA-2023:5480 (opens in a new tab)
- access.redhat.com/errata/RHSA-2023:6107 (opens in a new tab)
- access.redhat.com/errata/RHSA-2023:6112 (opens in a new tab)
- access.redhat.com/errata/RHSA-2023:7653 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2023-4853 (opens in a new tab)
- access.redhat.com/security/vulnerabilities/RHSB-2023-002 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2238034 (opens in a new tab)