Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.46% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-2742High confidence
Unauthorized session creation via reserved framework path access
vaadin · vaadin
5.3MediumCVSS 4.0
Scheduled
Patch availableMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:Medium, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs vaadin vaadin and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Open-source package ranges16 source-attributed ranges
These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.
| Ecosystem and package | Affected range | First fixed version | Evidence |
|---|---|---|---|
| Mavencom.vaadin:flow-server | ECOSYSTEM: introduced 0; fixed 14.14.1 | 14.14.1 | OSV record ↗aggregator derived · 10 Sep 2026 |
| Mavencom.vaadin:flow-server | ECOSYSTEM: introduced 23.0.0; fixed 23.6.7 | 23.6.7 | OSV record ↗aggregator derived · 10 Sep 2026 |
| Mavencom.vaadin:flow-server | ECOSYSTEM: introduced 24.0.0; fixed 24.9.8 | 24.9.8 | OSV record ↗aggregator derived · 10 Sep 2026 |
| Mavencom.vaadin:flow-server | ECOSYSTEM: introduced 25.0.0; fixed 25.0.2 | 25.0.2 | OSV record ↗aggregator derived · 10 Sep 2026 |
| Mavencom.vaadin:vaadin | ECOSYSTEM: introduced 25.0.0; fixed 25.0.2 | 25.0.2 | OSV record ↗aggregator derived · 10 Sep 2026 |
| Mavencom.vaadin:vaadin | ECOSYSTEM: introduced 24.0.0; fixed 24.9.8 | 24.9.8 | OSV record ↗aggregator derived · 10 Sep 2026 |
| Mavencom.vaadin:vaadin | ECOSYSTEM: introduced 23.0.0; fixed 23.6.7 | 23.6.7 | OSV record ↗aggregator derived · 10 Sep 2026 |
| Mavencom.vaadin:vaadin | ECOSYSTEM: introduced 0; fixed 14.14.1 | 14.14.1 | OSV record ↗aggregator derived · 10 Sep 2026 |
| mavencom.vaadin:flow-server | < 14.14.1 | 14.14.1 | GitHub advisory ↗github reviewed aggregator · 11 Mar 2026 |
| mavencom.vaadin:flow-server | >= 23.0.0, < 23.6.7 | 23.6.7 | GitHub advisory ↗github reviewed aggregator · 11 Mar 2026 |
| mavencom.vaadin:flow-server | >= 24.0.0, < 24.9.8 | 24.9.8 | GitHub advisory ↗github reviewed aggregator · 11 Mar 2026 |
| mavencom.vaadin:flow-server | >= 25.0.0, < 25.0.2 | 25.0.2 | GitHub advisory ↗github reviewed aggregator · 11 Mar 2026 |
| mavencom.vaadin:vaadin | >= 25.0.0, < 25.0.2 | 25.0.2 | GitHub advisory ↗github reviewed aggregator · 11 Mar 2026 |
| mavencom.vaadin:vaadin | >= 24.0.0, < 24.9.8 | 24.9.8 | GitHub advisory ↗github reviewed aggregator · 11 Mar 2026 |
| mavencom.vaadin:vaadin | >= 23.0.0, < 23.6.7 | 23.6.7 | GitHub advisory ↗github reviewed aggregator · 11 Mar 2026 |
| mavencom.vaadin:vaadin | < 14.14.1 | 14.14.1 | GitHub advisory ↗github reviewed aggregator · 11 Mar 2026 |
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Patch available01
What, why and how
An authentication bypass vulnerability exists in Vaadin 14.0.0 through 14.14.0, 23.0.0 through 23.6.6, 24.0.0 through 24.9.7 and 25.0.0 through 25.0.1, applications using Spring Security due to inconsistent path pattern matching of reserved framework paths. Accessing the /VAADIN endpoint without a trailing slash bypasses security filters, and allowing unauthenticated users to trigger framework initialization and create sessions without proper authorization. Users of affected versions using Spring Security should upgrade as follows: 14.0.0-14.14.0 upgrade to 14.14.1, 23.0.0-23.6.6 to 23.6.7, 24.0.0 - 24.9.7 to 24.9.8, and 25.0.0-25.0.1 upgrade to 25.0.2 or newer. Please note that Vaadin versions 10-13 and 15-22 are no longer supported and you should update either to the latest 14, 23, 24, 25 version.
What
An authentication bypass vulnerability exists in Vaadin 14.0.0 through 14.14.0, 23.0.0 through 23.6.6, 24.0.0 through 24.9.7 and 25.0.0 through 25.0.1, applications using Spring Security due to inconsistent path pattern matching of reserved framework paths. Accessing the /VAADIN endpoint without a trailing slash bypasses security filters, and allowing unauthenticated users to trigger framework initialization and create sessions without proper authorization. Users of affected versions using Spring Security should upgrade as follows: 14.0.0-14.14.0 upgrade to 14.14.1, 23.0.0-23.6.6 to 23.6.7, 24.0.0 - 24.9.7 to 24.9.8, and 25.0.0-25.0.1 upgrade to 25.0.2 or newer. Please note that Vaadin versions 10-13 and 15-22 are no longer supported and you should update either to the latest 14, 23, 24, 25 version.
Why
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may bypass an access boundary or take over an account.
What
An authentication bypass vulnerability exists in Vaadin 14.0.0 through 14.14.0, 23.0.0 through 23.6.6, 24.0.0 through 24.9.7 and 25.0.0 through 25.0.1, applications using Spring Security due to inconsistent path pattern matching of reserved framework paths. Accessing the /VAADIN endpoint without a trailing slash bypasses security filters, and allowing unauthenticated users to trigger framework initialization and create sessions without proper authorization. Users of affected versions using Spring Security should upgrade as follows: 14.0.0-14.14.0 upgrade to 14.14.1, 23.0.0-23.6.6 to 23.6.7, 24.0.0 - 24.9.7 to 24.9.8, and 25.0.0-25.0.1 upgrade to 25.0.2 or newer. Please note that Vaadin versions 10-13 and 15-22 are no longer supported and you should update either to the latest 14, 23, 24, 25 version.
Why
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may bypass an access boundary or take over an account.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- a network path → Improper Access Control → bypass an access boundary or take over an account
- Attack surface
- Network
- Privileges required
- Low: a basic authenticated account is required
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Not a CVSS 4.0 base metric
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-284 ↗
CWE-284: Improper Access Control. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L/S:N/AU:Y/R:A/V:D/RE:L/U:AmberCommon Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.VCNoneVulnerable-system confidentiality: No direct loss is represented by this metric.VINoneVulnerable-system integrity: No direct loss is represented by this metric.VALowVulnerable-system availability: A successful attack can cause a limited loss.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SALowSubsequent-system availability: A successful attack can cause a limited loss.- Post-exploitation / living off the land
- Stolen credentials, tokens and legitimate administration functions may provide continued access without deploying a large custom toolset.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Patch available
- Affected
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 10 Mar 2026 · Last source change 16 Mar 2026, 10:52 UTC · CWE-284 · Improper Access Control
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-10498
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
CVE published
Fixed release or patch reference recorded
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.