How severe is CVE-2015-6409?

CVE-2015-6409 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2015-6409 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2015-6409?

CVE-2015-6409 affects Cisco Jabber. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2015-6409?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2015-6409 published?

CVE-2015-6409 was published on 2015-12-26 and last updated on 2026-06-17.

CVE-2015-6409

CVE-2015-6409 is a medium-severity vulnerability in Cisco Jabber with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-200.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
CVSS v2: 4.3
EPSS exploit prediction: 1% (70th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: Cisco Jabber
Published: 2015-12-26
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2015-6409?: 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.
How severe is CVE-2015-6409?: CVE-2015-6409 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2015-6409 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2015-6409?: CVE-2015-6409 affects Cisco Jabber. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2015-6409?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2015-6409 published?: CVE-2015-6409 was published on 2015-12-26 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:cisco:jabber:10.6\(2\):*:*:*:*:windows:*:*

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