CVE-2015-6409

MEDIUMNVD 5.95.9—

5.9

Cisco Jabber 10.6.x, 11.0.x, and 11.1.x on Windows allows man-in-the-middle attackers to conduct STARTTLS downgrade attacks and trigger cleartext XMPP sessions via unspecified vectors, aka Bug ID CSCuw87419.

CVSS v3: 5.9
EG Score: 5.9(medium)
EPSS: 49.4%
KEV: Not listed

Published

December 26, 2015

Last Modified

May 6, 2026

References (8)

psirt@ciscohttp://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20151224-jab
psirt@ciscohttp://www.securityfocus.com/bid/79678
psirt@ciscohttp://www.securitytracker.com/id/1034540
psirt@ciscohttp://www.synacktiv.com/ressources/cisco_jabber_starttls_downgrade.pdf
af854a3a-2127-422b-91ae-364da2661108http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20151224-jab
af854a3a-2127-422b-91ae-364da2661108http://www.securityfocus.com/bid/79678
af854a3a-2127-422b-91ae-364da2661108http://www.securitytracker.com/id/1034540
af854a3a-2127-422b-91ae-364da2661108http://www.synacktiv.com/ressources/cisco_jabber_starttls_downgrade.pdf

Data Freshness Timeline

(refreshed 8× in last 7d / 20× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

2026-06-08 14:14 UTCEPSS rescore
2026-06-07 15:22 UTCEPSS rescore
2026-06-06 13:45 UTCEPSS rescore
2026-06-05 22:44 UTCEPSS rescore
2026-06-05 06:08 UTCEPSS rescore
2026-06-05 06:08 UTCEPSS rescore
2026-06-04 13:10 UTCEPSS rescore
2026-06-04 13:10 UTCEPSS rescore
2026-06-02 20:10 UTCEPSS rescore
2026-06-01 13:49 UTCEPSS rescore
2026-06-01 13:49 UTCEPSS rescore
2026-05-31 22:28 UTCEPSS rescore
2026-05-31 22:28 UTCEPSS rescore
2026-05-31 00:14 UTCEPSS rescore
2026-05-29 13:41 UTCEPSS rescore
2026-05-28 13:42 UTCEPSS rescore
2026-05-28 13:42 UTCEPSS rescore
2026-05-27 13:38 UTCEPSS rescore
2026-05-27 13:38 UTCEPSS rescore
2026-05-26 13:41 UTCEPSS rescore

Frequently asked(5)

What is CVE-2015-6409?

CVE-2015-6409 is a medium vulnerability published on December 26, 2015. Cisco Jabber 10.6.x, 11.0.x, and 11.1.x on Windows allows man-in-the-middle attackers to conduct STARTTLS downgrade attacks and trigger cleartext XMPP sessions via unspecified vectors, aka Bug ID CSCuw87419.

When was CVE-2015-6409 disclosed?

CVE-2015-6409 was first published in the National Vulnerability Database on December 26, 2015, with the most recent update on May 6, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2015-6409 actively exploited?

CVE-2015-6409 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 49.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2015-6409?

CVE-2015-6409 has a CVSS v3 base score of 5.9 (NVD).

How do I remediate CVE-2015-6409?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2015-6409, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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CVE-2015-6409

📅 Published

🔄 Last Modified

🔗 References (8)