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Fencer Vulns
high 7.5

CVE-2026-15076 json

In versions up to and including 4.5.29 (4.x branch) and 5.1.4 (5.x branch), the WebClientSession component of Eclipse Vert.x Web Client doe…

published 2026-07-14 3 mo ago modified 2026-10-24 15 d ago also EUVD-2026-43637

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 9%
public exploits
0
none known

Summary

In versions up to and including 4.5.29 (4.x branch) and 5.1.4 (5.x branch), the WebClientSession component of Eclipse Vert.x Web Client does not validate that the Domain attribute of a Set-Cookie response header matches the originating server's domain, in violation of RFC 6265 section 5.3. An attacker who controls any server that the victim application contacts can inject a cookie scoped to an arbitrary third-party domain; because the session store performs no cross-domain ownership check, it stores and later transmits that cookie to the targeted domain.

When the victim application subsequently sends a request to the targeted domain using the same WebClientSession, it presents the attacker-injected cookie, causing the receiving service to process the request under the attacker's account. Sensitive data included in the victim application's requests, such as payment amounts, card details, or other API payloads, may then be accessible to the attacker through their own account on that service.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-15076 updated cvss 7.5

io.vertx/vertx-web: Eclipse Vert.x Web Client: Information disclosure via improper cookie domain validation

  • Red Hat OpenShift Serverless openshift-serverless-1/kn-eventing-integrations-log-sink-rhel9, openshift-serverless-1/kn-eventing-integrations-aws-s3-sink-rhel9, openshift-serverless-1/kn-eventing-integrations-aws-sns-sink-rhel9, openshift-serverless-1/kn-eventing-integrations-aws-sqs-sink-rhel9, openshift-serverless-1/kn-eventing-integrations-timer-source-rhel9, openshift-serverless-1/kn-eventing-integrations-aws-s3-source-rhel9, +2 more Red Hat build of Apache Camel - HawtIO 4 vertx-web-client 4.5.28.redhat-00001 Red Hat build of Apache Camel 4 for Quarkus 3 vertx-web-client 4.5.28.redhat-00001 Red Hat build of Apicurio Registry 3 vertx-web-client 4.5.28.redhat-00001
    affected: workaround, no fix available
  • Red Hat build of Debezium 3 vertx-web-client 4.5.28.redhat-00001
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Build of Keycloak vertx-web-common 4.5.28.redhat-00001
    affected: workaround, no fix available
  • Red Hat Cryostat 4 on RHEL 9 cryostat/cryostat-rhel9 4.2.0-14, cryostat/jfr-datasource-rhel9 4.2.0-14, cryostat/cryostat-reports-rhel9 4.2.0-14
    fixed: vendor fix RHSA-2026:68333
  • Red Hat Build of Apache Camel 3.33.2.SP3 vertx-web-client 4.5.30.redhat-00001
    fixed: vendor fix RHSA-2026:48118
  • Red Hat build of Apache Camel 4.18.3 for Spring Boot 3.5.16
    fixed: vendor fix RHSA-2026:54622
  • Red Hat build of Keycloak 26.4.14
    fixed: vendor fix RHSA-2026:50846
  • Red Hat build of Keycloak 26.6.5
    fixed: vendor fix RHSA-2026:50848
show 8 more
  • Red Hat build of Quarkus 3.27.4.SP3 vertx-web-client 4.5.30.redhat-00001
    fixed: vendor fix RHSA-2026:47189
  • Red Hat build of Quarkus 3.33.2.SP3 vertx-web-client 4.5.30.redhat-00001
    fixed: vendor fix RHSA-2026:47172
  • Red Hat OpenShift Dev Spaces 3.30 devspaces/server-rhel9 1787757597
    fixed: vendor fix RHSA-2026:62260
  • Red Hat OpenShift Dev Spaces 3.31 devspaces/multicluster-redirector-rhel9 1792491532
    fixed: vendor fix RHSA-2026:90321
  • Red Hat Streams for Apache Kafka 3.2.1
    fixed: vendor fix RHSA-2026:54435
  • Red Hat Cryostat 4 on RHEL 9 cryostat/cryostat-db-rhel9 4.2.0-22, cryostat/cryostat-storage-rhel9 4.2.0-22, cryostat/cryostat-rhel9-operator 4.2.0-21, cryostat/cryostat-operator-bundle 4.2.0-12, cryostat/cryostat-agent-init-rhel9 0.7.0-12, cryostat/cryostat-grafana-dashboard-rhel9 4.2.0-14, +1 more Red Hat Build of Apache Camel 3.33.2.SP3 jimfs 1.1, jna 5.8.0, bcel 6.7.0, bson 5.6.4, gax 2.74.1, icu4j 78.2, +1630 more Red Hat build of Quarkus 3.27.4.SP3 jna 5.8.0, db2 1.21.4, h2 2.3.230, y18n 5.0.8, cliui 8.0.1, guice 5.1.0, +1009 more Red Hat build of Quarkus 3.33.2.SP3 jna 5.8.0, bson 5.6.4, h2 2.4.240, y18n 5.0.8, cliui 8.0.1, guice 5.1.0, +1018 more
    not affected: vulnerable code not present
  • Red Hat Data Grid 8 vertx-web-client 4.5.28.redhat-00001
    not affected: component not present
  • Red Hat JBoss Enterprise Application Platform Expansion Pack vertx-web-client 4.5.28.redhat-00001 Red Hat OpenShift AI (RHOAI) rhoai/odh-trustyai-service-rhel9 Red Hat OpenShift Dev Spaces 3.30 devspaces/udi-rhel9 1787764814, devspaces/code-rhel9 1787762793, devspaces/openvsx-rhel9 1787759145, devspaces/traefik-rhel9 1787756799, devspaces/udi-base-rhel9 1787761882, devspaces/code-sshd-rhel9 1787762385, +10 more Red Hat OpenShift Dev Spaces 3.31 devspaces/udi-rhel9 1792708612, devspaces/code-rhel9 1792599388, devspaces/server-rhel9 1792775639, devspaces/openvsx-rhel9 1792494821, devspaces/traefik-rhel9 1792464177, devspaces/udi-base-rhel9 1792686842, +9 more Red Hat streams for Apache Kafka 2 vertx-web-client 4.5.28.redhat-00001
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
3 mo ago

Exploit prediction

0.20% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 8.2 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
CNA 4.0 8.2 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected products

  • Eclipse Foundation Eclipse Vert.x

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.