CVE-2026-15076

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.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://gitlab.eclipse.org/security/cve-assignment/-/work_items/162	Issue Tracking

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:eclipse:vert.x::::::::
	cpe:2.3:a:eclipse:vert.x::::::::

History

14 Jul 2026, 20:53

Type	Values Removed	Values Added
First Time		Eclipse vert.x Eclipse
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 7.5
References	~~() https://gitlab.eclipse.org/security/cve-assignment/-/work_items/162 -~~	() https://gitlab.eclipse.org/security/cve-assignment/-/work_items/162 - Issue Tracking
CPE		cpe:2.3:a:eclipse:vert.x::::::::

14 Jul 2026, 09:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-07-14 09:16

Updated : 2026-07-14 20:53

NVD link : CVE-2026-15076

Mitre link : CVE-2026-15076

CVE.ORG link : CVE-2026-15076

JSON object : View

Products Affected

eclipse

vert.x

CWE

CWE-346

Origin Validation Error

{"id": "CVE-2026-15076", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-15076", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-07-14T12:20:15.334764Z"}}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 3.6, "exploitabilityScore": 3.9}], "cvssMetricV40": [{"type": "Secondary", "source": "emo@eclipse.org", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 8.2, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "HIGH", "valueDensity": "NOT_DEFINED", "vectorString": "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", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "NONE", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "emo@eclipse.org", "affectedData": [{"repo": "https://github.com/vert-x3/vertx-web", "vendor": "Eclipse Foundation", "product": "Eclipse Vert.x", "versions": [{"status": "affected", "version": "4.0.0", "versionType": "semver", "lessThanOrEqual": "4.5.29"}, {"status": "affected", "version": "5.0.0", "versionType": "semver", "lessThanOrEqual": "5.1.4"}], "defaultStatus": "unaffected"}]}], "published": "2026-07-14T09:16:40.313", "references": [{"url": "https://gitlab.eclipse.org/security/cve-assignment/-/work_items/162", "tags": ["Issue Tracking"], "source": "emo@eclipse.org"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "emo@eclipse.org", "description": [{"lang": "en", "value": "CWE-346"}]}], "descriptions": [{"lang": "en", "value": "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.\nAn 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.\n\n\n\n\nWhen 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."}], "lastModified": "2026-07-14T20:53:32.310", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:eclipse:vert.x:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "DB153CF0-70BB-4DE1-87EE-92477ED3BD1D", "versionEndIncluding": "4.5.29", "versionStartIncluding": "4.0.0"}, {"criteria": "cpe:2.3:a:eclipse:vert.x:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "20CCD041-C4F7-4580-ABF9-91EF0C16E7F1", "versionEndIncluding": "5.1.4", "versionStartIncluding": "5.0.0"}], "operator": "OR"}]}], "sourceIdentifier": "emo@eclipse.org"}