How severe is CVE-2026-6860?

No CVSS score has been assigned to CVE-2026-6860 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-6860?

CVE-2026-6860 affects the following packages: io.vertx:vertx-core (Maven), io.vertx:vertx-core (Maven), io.vertx:vertx-core (Maven), io.vertx:vertx-core (Maven). Ecosystems affected: Maven.

How do I fix CVE-2026-6860?

No patched version of io.vertx:vertx-core has shipped for CVE-2026-6860 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

How do I detect CVE-2026-6860 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.vertx:vertx-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-6860 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-6860?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-6860 can be triaged on real exposure rather than presence alone.

Is CVE-2026-6860 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-6860 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-6860?

CVE-2026-6860 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 15th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-6860?

CVE-2026-6860 is classified as CWE-770 (CWE-770), CWE-295 (CWE-295). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-6860 published, and has it been updated?

CVE-2026-6860 was published on May 6, 2026 and was last updated on August 12, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕ Maven

Not in CISA KEV

CVE-2026-6860 — vertx-core

Fix: eclipse-vertx/vert.x#6102

CVE-2026-6860 is a CWE-770 vulnerability in io.vertx:vertx-core. A fix is available for io.vertx:vertx-core — see the affected versions and patch details below.

Vert.x has a DoS via unbounded server-side SNI SslContext cache growth

Also known asGHSA-3g76-f9xq-8vp6

Published

May 6, 2026

Updated

Aug 12, 2026

Affected

4 pkgs

Patched

2 / 4

Exploits

None indexed

Exploitation data as of Sep 18, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-6860.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs15th percentile — riskier than 15% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

4 pkgs affected

☕io.vertx:vertx-core☕io.vertx:vertx-core☕io.vertx:vertx-core☕io.vertx:vertx-core

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

A TCP client can perform a TLS handshake and present the server name extension with a server name that is accepted by a server wildcard name, e.g. if the server is configured with a certificate accepting *.example.com, any XYZ.example.com where xyz is a valid name can be used.

Affected Packages

4 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`io.vertx:vertx-core`	≥ 4.3.4	No fix
☕Maven	`io.vertx:vertx-core`	≥ 4.4.0	No fix
☕Maven	`io.vertx:vertx-core`	≥ 4.5.0&&< 4.5.27	4.5.27`io.vertx:vertx-core:4.5.27`
☕Maven	`io.vertx:vertx-core`	≥ 5.0.0&&< 5.0.12	5.0.12`io.vertx:vertx-core:5.0.12`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.vertx:vertx-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
No patched version of io.vertx:vertx-core has shipped for CVE-2026-6860 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-6860 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2026-6860. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

This flaw is rated as Moderate because a remote attacker can trigger a denial of service in Red Hat products that use `eclipse-vertx/vert.x` and are configured with TLS wildcard server names. Exploitation occurs during the TLS handshake, impacting service availability without affecting data confidentiality or…

Product	Fixed in	Advisory
Cryostat 4 on RHEL 9	`cryostat/cryostat-reports-rhel9:4.2.0-13`	RHSA-2026:48151
Red Hat build of Apache Camel 4.18.3 for Spring Boot 3.5.16	`vertx-core`	RHSA-2026:54622
Red Hat build of Keycloak 26.4	`rhbk/keycloak-operator-bundle:26.4.13-1`	RHSA-2026:30050
Red Hat build of Keycloak 26.4.13	`rhbk/keycloak-rhel9`	RHSA-2026:30049
Red Hat build of Keycloak 26.6	`rhbk/keycloak-operator-bundle:26.6.4-2`	RHSA-2026:30084
Red Hat build of Keycloak 26.6.4	`rhbk/keycloak-rhel9`	RHSA-2026:30083
Red Hat build of Quarkus 3.27.4.SP1	`vertx-core`	RHSA-2026:26018
Red Hat build of Quarkus 3.33.2.SP1	`vertx-core`	RHSA-2026:26017

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2026-6860 in your dependencies?

O3 Security finds CVE-2026-6860 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works