VulnerabilityPublished 10 Oct 2023Updated 29 Oct 2025

CVE-2023-42795: Apache Tomcat · Incomplete Cleanup

Affects Apache TomcatSource CVE Database V5

Not known to be exploited · CVSS 5.3 Medium : upgrade to 8.5.94 when convenient.

Data as of 26 Oct 2026, 12:54 UTC

CVSS 3.1 base score

5.3Medium

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

EPSS: 2.5% chance of exploitation in 30 days – higher than 84% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 8.5.94

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
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: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within 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 10 Oct 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 26 Oct 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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.

What to do

Upgrade org.apache.tomcat/tomcat to 8.5.94.

Affected software

Product	Affected	Fixed in
Mavenorg.apache.tomcat/tomcat`pkg:maven/org.apache.tomcat/tomcat`Other threats	Affected 8.5.0 <8.5.94	Fixed in 8.5.94

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

AI-suggested

European organizations should immediately assess their Apache Tomcat deployments to identify affected versions. The primary mitigation is to upgrade to the fixed versions: 8.5.94 or later, 9.0.81 or later, 10.1.14 or later, or 11.0.0-M12 or later. If immediate upgrading is not feasible, organizations should implement strict network controls to limit access to Tomcat servers, such as IP whitelisting and web application firewalls (WAFs) configured to detect anomalous HTTP request patterns. Additionally, review and minimize sensitive data exposure in HTTP responses and ensure session management follows best practices to reduce the impact of potential leaks. Conduct thorough logging and monitoring to detect unusual request patterns that might indicate exploitation attempts. Regularly audit and sanitize application code to avoid storing sensitive data in server-side objects unnecessarily. Finally, maintain an up-to-date inventory of Tomcat instances and enforce patch management policies to prevent similar vulnerabilities from persisting.

Description

Incomplete Cleanup vulnerability in Apache Tomcat.When recycling various internal objects in Apache Tomcat from 11.0.0-M1 through 11.0.0-M11, from 10.1.0-M1 through 10.1.13, from 9.0.0-M1 through 9.0.80 and from 8.5.0 through 8.5.93, an error could cause Tomcat to skip some parts of the recycling process leading to information leaking from the current request/response to the next. Older, EOL versions may also be affected. Users are recommended to upgrade to version 11.0.0-M12 onwards, 10.1.14 onwards, 9.0.81 onwards or 8.5.94 onwards, which fixes the issue.

Impact

For European organizations, the incomplete cleanup vulnerability in Apache Tomcat can lead to unauthorized disclosure of sensitive information processed by web applications, including personal data protected under GDPR. This leakage could expose session tokens, user credentials, or other confidential information to attackers, potentially facilitating further attacks such as session hijacking or unauthorized access. Organizations in sectors like finance, healthcare, government, and critical infrastructure that rely heavily on Tomcat for web services are particularly at risk. The breach of confidentiality could result in regulatory penalties, reputational damage, and loss of customer trust. Since the vulnerability does not affect system integrity or availability, the immediate operational impact may be limited, but the data exposure risk is significant. The ease of remote exploitation without authentication increases the threat level, especially in public-facing web applications. European entities with strict data protection requirements must prioritize patching to avoid compliance violations and data breaches.

CWE-459Incomplete Cleanup (opens in a new tab)
Base weakness
The product does not properly "clean up" and remove temporary or supporting resources after they have been used.
Architecture and Design · Implementation
Temporary files and other supporting resources should be deleted/released immediately after they are no longer needed.
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 29 Oct 2025, 12:22 UTC

WeaknessesCWE-459

Technical details

References

Community reviews

Related threats