VulnerabilityPublished 3 Nov 2026

CVE-2026-118489: Eclipse Vert.x · Information Exposure

Affects Eclipse Vert.xSource CVE Database V5

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Not known to be exploited · CVSS 7.5 High.

Data as of 3 Nov 2026, 15:13 UTC

CVSS 3.1 base score

7.5High

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

Thin evidence

One scorer or none

CVSS scores by source
CNA (eclipse)	CVSS 3.1	7.5

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
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: 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: 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 3 Nov 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 3 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.

What to do

Affected software

Product	Affected	Fixed in
Eclipse FoundationEclipse Vert.x	Affected >=4.0.0 <=4.5.35 >=5.0.0 <=5.2.2	Fixed in–
Mavenio.vertx/vertx-web`pkg:maven/io.vertx/vertx-web`Other threats	Affected >=4.0.0 <=4.5.35 >=5.0.0 <=5.2.2	Fixed in–

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

AI-suggested

Until a fix is available, avoid sharing a single CachingWebClient instance across multiple users or ensure that cacheable responses are properly marked with 'private' or 'no-store' directives to prevent caching of sensitive data.

Description

Eclipse Vert.x versions 4.0.0 through 4.5.35 and 5.0.0 through 5.2.2 contain a vulnerability where a shared CachingWebClient improperly caches user-specific responses. This can lead to sensitive information exposure when cached responses intended for one user are served to others, potentially disclosing authenticated content or session cookies. This flaw can enable session fixation or hijacking attacks.

Impact

The vulnerability leads to unauthorized disclosure of sensitive information by serving cached responses specific to one user to other users. This can expose authenticated content or session cookies, increasing the risk of session fixation or hijacking. The confidentiality of user data is compromised, but there is no direct impact on integrity or availability.

Summary

In Eclipse Vert.x versions >=4.0.0 <=4.5.35 and >=5.0.0 <=5.2.2, the shared use of a CachingWebClient across multiple users causes user-specific cacheable responses that lack 'private' or 'no-store' cache directives to be stored in a shared cache tier. Consequently, responses intended for one user may be served to other users requesting the same URL. This behavior can expose sensitive information such as authenticated content or session cookies, which may facilitate session fixation or hijacking.

CWE-200Exposure of Sensitive Information to an Unauthorized Actor (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #20OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Separation of Privilege
Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
OWASP Cheat Sheets
Error Handling (opens in a new tab)
Logging (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.4 (opens in a new tab)
V14.3.3 (opens in a new tab)
V7.3.3 (opens in a new tab)
Attack patterns
Subverting Environment Variable Values (opens in a new tab)
ICMP Echo Request Ping (opens in a new tab)
TCP SYN Scan (opens in a new tab)
Enumerate Mail Exchange (MX) Records (opens in a new tab)
DNS Zone Transfers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-524Use of Cache Containing Sensitive Information (opens in a new tab)
Base weakness
The code uses a cache that contains sensitive information, but the cache can be read by an actor outside of the intended control sphere.
Architecture and Design
Protect information stored in cache.
Architecture and Design
Do not store unnecessarily sensitive information in the cache.
Architecture and Design
Consider using encryption in the cache.
OWASP ASVS 4.0.3
V8.1.1 (opens in a new tab)
V8.1.2 (opens in a new tab)
Attack patterns
Lifting Sensitive Data Embedded in Cache (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 3 Nov 2026, 14:59 UTC

WeaknessesCWE-200, CWE-524

Technical details

References

Community reviews

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