← Vulnerability feed

Vulnerability record · CVE-2026-15554 · published 11 August 2026

CVE-2026-15554: Improper certificate validation vulnerability

the Undertow AJP listener honours forged ssl_cert and is_ssl AJP attributes without requiring any shared-secret authentication. This enables an unauthenticated attacker with direct TCP access to port 8009 to bypass CLIENT-CERT authentication by injecting a forged X.509 certificate via the AJP protocol.

7.4 CVSS 3.1 High EPSS 0.35% · top 73.5% CWE-295 · Improper certificate validation Awaiting Analysis
7.4CVSS 3.1 base score
0.35%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
10References
25 Sep 2026Last modified by NVD

Description

the Undertow AJP listener honours forged ssl_cert and is_ssl AJP attributes without requiring any shared-secret authentication. This enables an unauthenticated attacker with direct TCP access to port 8009 to bypass CLIENT-CERT authentication by injecting a forged X.509 certificate via the AJP protocol.

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

References

LinkTags
https://access.redhat.com/errata/RHSA-2026:53644
https://access.redhat.com/errata/RHSA-2026:53645
https://access.redhat.com/errata/RHSA-2026:53646
https://access.redhat.com/errata/RHSA-2026:53806
https://access.redhat.com/errata/RHSA-2026:70228
https://access.redhat.com/errata/RHSA-2026:70229
https://access.redhat.com/errata/RHSA-2026:70230
https://access.redhat.com/errata/RHSA-2026:70277
https://access.redhat.com/security/cve/CVE-2026-15554
https://bugzilla.redhat.com/show_bug.cgi?id=2480601

Track CVE-2026-15554 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2026-85102Checkpoint gaia embedded improper certificate validation vulnerabilityImproper certificate trust validation during VPN negotiation in Check Point Quantum Security Gateway may allow an unauthenticated remote attacker to …KEVEPSS 0.99%5.5CVE-2023-41991Apple iOS, iPadOS and macOS certificate validation bypassApple iOS, iPadOS and macOS contain an improper certificate validation flaw (CWE-295) that lets a malicious app bypass signature validation. Apple st…KEVEPSS 13%analysed7.8CVE-2023-20963Android WorkSource parcel mismatch local privilege escalationCVE-2023-20963 is a parcel mismatch in Android's WorkSource component that allows a local attacker to escalate privileges without additional executio…KEVEPSS 1.5%analysed8.8CVE-2022-26923Microsoft Active Directory Domain Services certificate validation privilege escalationActive Directory Domain Services fails to properly validate certificate attributes, allowing a low-privileged domain user to obtain a certificate tha…KEVEPSS 84%analysed8.0CVE-2022-20703Cisco Small Business RV Series Routers stack-based buffer overflowCVE-2022-20703 covers multiple vulnerabilities in Cisco Small Business RV160, RV260, RV340 and RV345 Series Routers, including a stack-based buffer o…KEVEPSS 9.2%analysed8.1CVE-2020-0601Windows CryptoAPI ECC certificate validation spoofing flawWindows CryptoAPI (Crypt32.dll) improperly validates Elliptic Curve Cryptography certificates, allowing a spoofed code-signing certificate to be trus…KEVEPSS 89%analysed

Source: NIST National Vulnerability Database (record CVE-2026-15554), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.