How severe is CVE-2016-6357?

CVE-2016-6357 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2016-6357 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-6357?

CVE-2016-6357 primarily affects Cisco Email Security Appliance. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-6357?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2016-6357 published?

CVE-2016-6357 was published on 2016-10-28 and last updated on 2026-06-17.

CVE-2016-6357

CVE-2016-6357 is a high-severity vulnerability in Cisco Email Security Appliance with a CVSS 3.x base score of 7.5. 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-388.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (82nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-388
Affected product: Cisco Email Security Appliance
Published: 2016-10-28
Last modified: 2026-06-17

Description

A vulnerability in the configured security policies, including drop email filtering, in Cisco AsyncOS for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass a configured drop filter by using an email with a corrupted attachment. More Information: CSCuz01651. Known Affected Releases: 10.0.9-015 9.7.1-066 9.9.6-026.

Frequently asked questions

What is CVE-2016-6357?: A vulnerability in the configured security policies, including drop email filtering, in Cisco AsyncOS for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass a configured drop filter by using an email with a corrupted attachment. More Information: CSCuz01651. Known Affected Releases: 10.0.9-015 9.7.1-066 9.9.6-026.
How severe is CVE-2016-6357?: CVE-2016-6357 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2016-6357 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-6357?: CVE-2016-6357 primarily affects Cisco Email Security Appliance. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-6357?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2016-6357 published?: CVE-2016-6357 was published on 2016-10-28 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:cisco:email_security_appliance:9.7.1-066:*:*:*:*:*:*:*
cpe:2.3:a:cisco:email_security_appliance:9.9.6-026:*:*:*:*:*:*:*

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