VulnerabilityPublished 23 Sep 2026Updated 17 Oct 2026

CVE-2026-86246: Initialization of a resource with an insecure default vulnerability in Apache Tomcat Native enabled insecure options by default including

Affects tomcat-nativeSource GCVE Database

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Authoritative record:CVE-2026-86246· Critical 9.1

Not known to be exploited · CVSS 9.1 Critical · fixed in 2.0.16 : patch tomcat-native as a priority.

Data as of 7 Nov 2026, 23:24 UTC

CVSS 3.1 base score

9.1Critical

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 28% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.0.16

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 23 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 8 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-9p2m-jvmj-wh8q

What to do

Affected software

Product	Affected	Fixed in
Ubuntu 16.04 LTStomcat-native`pkg:deb/ubuntu/tomcat-native?arch=source&distro=xenial`Other threats	Affected =1.1.33-1	Fixed in–
Ubuntu 18.04 LTStomcat-native`pkg:deb/ubuntu/tomcat-native?arch=source&distro=bionic`Other threats	Affected 1.2.14-1 – 1.2.21-1~18.04.1build1 5 affected builds	Fixed in–
Ubuntu 20.04 LTStomcat-native`pkg:deb/ubuntu/tomcat-native?arch=source&distro=focal`Other threats	Affected =1.2.23-1	Fixed in–
Ubuntu 22.04 LTStomcat-native`pkg:deb/ubuntu/tomcat-native?arch=source&distro=jammy`Other threats	Affected =1.2.26-1 =1.2.31-1 =1.2.31-1build1	Fixed in–
Ubuntu 24.04 LTStomcat-native`pkg:deb/ubuntu/tomcat-native?arch=source&distro=noble`Other threats	Affected 1.2.35-1 – 2.0.14-1~24.04.1 4 affected builds	Fixed in–
Ubuntu 26.10tomcat-native`pkg:deb/ubuntu/tomcat-native?arch=source&distro=stonking`Other threats	Affected =1.3.1-1build1 =2.0.14-1 =2.0.15~us1-0ubuntu1	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade affected Apache Tomcat Native versions to 2.0.16 or later, or 1.3.9 or later, where the insecure default options are disabled by default. No other mitigation is indicated. Patch status is confirmed fixed in these versions.

Description

Apache Tomcat Native versions 2.0.0 through 2.0.15 and 1.3.0 through 1.3.8 have a vulnerability where insecure default options are enabled during resource initialization. These options include ALLOW_CLIENT_RENEGOTIATION, NO_EXTENDED_MASTER_SECRET, IGNORE_UNEXPECTED_EOF, and ALLOW_NO_DHE_KEX. This vulnerability is addressed in versions 2.0.16 and 1.3.9. The vulnerability has a CVSS score of 9.1, indicating high severity, with impacts on confidentiality and integrity but no impact on availability.

Impact

The vulnerability allows an attacker to exploit insecure default TLS/SSL options, which can lead to compromise of confidentiality and integrity of communications handled by Apache Tomcat Native. There is no impact on availability. The CVSS v3.1 score is 9.1 (critical), reflecting network attack vector, low attack complexity, no privileges required, no user interaction, and high confidentiality and integrity impact.

CWE-1188Initialization of a Resource with an Insecure Default (opens in a new tab)
Base weakness
The product initializes or sets a resource with a default that is intended to be changed by the product's installer, administrator, or maintainer, but the default is not secure.
OWASP Cheat Sheets
Forgot Password (opens in a new tab)
OWASP ASVS 4.0.3
V2.3.1 (opens in a new tab)
V2.6.2 (opens in a new tab)
V2.7.6 (opens in a new tab)
Attack patterns
Exploitation of Thunderbolt Protection Flaws (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 18 Oct 2026, 02:21 UTC

WeaknessesCWE-1188

Technical details

References

Community reviews

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