CVE-2018-8034

CVE-2018-8034 is a high-severity vulnerability in Apache Tomcat with a CVSS 3.x base score of 7.5. Its EPSS exploit-prediction score of 21% places it in the 97th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-295.

Key facts

• Severity: High (CVSS 3.x base score 7.5)
• CVSS v2: 5.0
• EPSS exploit prediction: 21% (97th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-295
• Affected product: Apache Tomcat
• Published: 2018-08-01
• Last modified: 2026-06-17

Description

The host name verification when using TLS with the WebSocket client was missing. It is now enabled by default. Versions Affected: Apache Tomcat 9.0.0.M1 to 9.0.9, 8.5.0 to 8.5.31, 8.0.0.RC1 to 8.0.52, and 7.0.35 to 7.0.88.

Frequently asked questions

What is CVE-2018-8034?

The host name verification when using TLS with the WebSocket client was missing. It is now enabled by default. Versions Affected: Apache Tomcat 9.0.0.M1 to 9.0.9, 8.5.0 to 8.5.31, 8.0.0.RC1 to 8.0.52, and 7.0.35 to 7.0.88.

How severe is CVE-2018-8034?

CVE-2018-8034 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2018-8034 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 21% (97th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-8034?

CVE-2018-8034 primarily affects Apache Tomcat. In total, 45 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-8034?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2018-8034 published?

CVE-2018-8034 was published on 2018-08-01 and last updated on 2026-06-17.

References

• http://mail-archives.us.apache.org/mod_mbox/www-announce/201807.mbox/%3C20180722091057.GA70283%40minotaur.apache.org%3E
• http://www.oracle.com/technetwork/security-advisory/cpuoct2018-4428296.html
• http://www.securityfocus.com/bid/104895
• http://www.securitytracker.com/id/1041374
• https://access.redhat.com/errata/RHSA-2019:0130
• https://access.redhat.com/errata/RHSA-2019:0131
• https://access.redhat.com/errata/RHSA-2019:0450
• https://access.redhat.com/errata/RHSA-2019:0451
• https://access.redhat.com/errata/RHSA-2019:1159
• https://access.redhat.com/errata/RHSA-2019:1160
• https://access.redhat.com/errata/RHSA-2019:1161
• https://access.redhat.com/errata/RHSA-2019:1162
• https://access.redhat.com/errata/RHSA-2019:1529
• https://access.redhat.com/errata/RHSA-2019:2205
• https://access.redhat.com/errata/RHSA-2019:3892
• https://lists.apache.org/thread.html/1dd0a59c1295cc08ce4c9e7edae5ad2268acc9ba55adcefa0532e5ba%40%3Cdev.tomcat.apache.org%3E
• https://lists.apache.org/thread.html/343558d982879bf88ec20dbf707f8c11255f8e219e81d45c4f8d0551%40%3Cdev.tomcat.apache.org%3E
• https://lists.apache.org/thread.html/388a323769f1dff84c9ec905455aa73fbcb20338e3c7eb131457f708%40%3Cdev.tomcat.apache.org%3E
• https://lists.apache.org/thread.html/3d19773b4cf0377db62d1e9328bf9160bf1819f04f988315086931d7%40%3Cdev.tomcat.apache.org%3E
• https://lists.apache.org/thread.html/5c0e00fd31efc11e147bf99d0f03c00a734447d3b131ab0818644cdb%40%3Cdev.tomcat.apache.org%3E
• https://lists.apache.org/thread.html/6af47120905aa7d8fe12f42e8ff2284fb338ba141d3b77b8c7cb61b3%40%3Cdev.tomcat.apache.org%3E
• https://lists.apache.org/thread.html/845312a10aabbe2c499fca94003881d2c79fc993d85f34c1f5c77424%40%3Cdev.tomcat.apache.org%3E
• https://lists.apache.org/thread.html/88855876c33f2f9c532ffb75bfee570ccf0b17ffa77493745af9a17a%40%3Cdev.tomcat.apache.org%3E
• https://lists.apache.org/thread.html/ac51944aef91dd5006b8510b0bef337adaccfe962fb90e7af9c22db4%40%3Cissues.activemq.apache.org%3E
• https://lists.apache.org/thread.html/b5e3f51d28cd5d9b1809f56594f2cf63dcd6a90429e16ea9f83bbedc%40%3Cdev.tomcat.apache.org%3E
• https://lists.apache.org/thread.html/e85e83e9954f169bbb77b44baae5a33d8de878df557bb32b7f793661%40%3Cdev.tomcat.apache.org%3E
• https://lists.apache.org/thread.html/eb6efa8d59c45a7a9eff94c4b925467d3b3fec8ba7697f3daa314b04%40%3Cdev.tomcat.apache.org%3E
• https://lists.apache.org/thread.html/r3bbb800a816d0a51eccc5a228c58736960a9fffafa581a225834d97d%40%3Cdev.tomcat.apache.org%3E
• https://lists.apache.org/thread.html/r48c1444845fe15a823e1374674bfc297d5008a5453788099ea14caf0%40%3Cdev.tomcat.apache.org%3E
• https://lists.apache.org/thread.html/r6ccee4e849bc77df0840c7f853f6bd09d426f6741247da2b7429d5d9%40%3Cdev.tomcat.apache.org%3E

Affected products (45)

• cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:8.0.0:rc1:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:8.0.0:rc10:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:8.0.0:rc2:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:8.0.0:rc3:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:8.0.0:rc4:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:8.0.0:rc5:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:8.0.0:rc6:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:8.0.0:rc7:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:8.0.0:rc8:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:8.0.0:rc9:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone1:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone10:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone11:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone12:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone13:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone14:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone15:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone16:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone17:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone18:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone19:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone2:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone20:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone21:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone22:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone23:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone24:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone25:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone26:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone27:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone3:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone4:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone5:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone6:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone7:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone8:*:*:*:*:*:*
• cpe:2.3:a:apache:tomcat:9.0.0:milestone9:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*

More vulnerabilities in Apache Tomcat

• CVE-2026-43512 — Critical (CVSS 9.8): DEPRECATED: Authentication Bypass Issues vulnerability in digest authentication in Apache Tomcat. This issue affects…
• CVE-2026-41293 — Critical (CVSS 9.8): Improper Input Validation vulnerability in Apache Tomcat. This issue affects Apache Tomcat: from 11.0.0-M1 through…
• CVE-2025-31651 — Critical (CVSS 9.8): Improper Neutralization of Escape, Meta, or Control Sequences vulnerability in Apache Tomcat. For a subset of unlikely…
• CVE-2025-24813 — Critical (CVSS 9.8): Path Equivalence: 'file.Name' (Internal Dot) leading to Remote Code Execution and/or Information disclosure and/or…
• CVE-2024-56337 — Critical (CVSS 9.8): Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability in Apache Tomcat. This issue affects Apache Tomcat:…
• CVE-2024-50379 — Critical (CVSS 9.8): Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability during JSP compilation in Apache Tomcat permits an RCE…

All CVEs affecting Apache Tomcat →

Other CWE-295 (Improper Certificate Validation) vulnerabilities

• CVE-2026-4370 — Critical (CVSS 10.0): A vulnerability was identified in Juju from version 3.2.0 until 3.6.19 and from version 4.0 until 4.0.4, where the…
• CVE-2026-30836 — Critical (CVSS 10.0): Step CA is an online certificate authority for secure, automated certificate management for DevOps. Versions 0.30.0-rc6…
• CVE-2025-68121 — Critical (CVSS 10.0): During session resumption in crypto/tls, if the underlying Config has its ClientCAs or RootCAs fields mutated between…
• CVE-2022-20703 — Critical (CVSS 10.0): Multiple vulnerabilities in Cisco Small Business RV160, RV260, RV340, and RV345 Series Routers could allow an attacker…
• CVE-2021-1471 — Critical (CVSS 9.9): Multiple vulnerabilities in Cisco Jabber for Windows, Cisco Jabber for MacOS, and Cisco Jabber for mobile platforms…
• CVE-2026-20184 — Critical (CVSS 9.8): A vulnerability in the integration of single sign-on (SSO) with Control Hub in Cisco Webex Services could have allowed…

Browse all CWE-295 (Improper Certificate Validation) vulnerabilities →