How severe is CVE-2016-6355?

CVE-2016-6355 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 none, integrity none, and availability high.

Is CVE-2016-6355 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-6355?

CVE-2016-6355 primarily affects Cisco Ios Xr. In total, 14 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-6355?

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-2016-6355 published?

CVE-2016-6355 was published on 2016-08-23 and last updated on 2026-06-17.

CVE-2016-6355

CVE-2016-6355 is a high-severity vulnerability in Cisco Ios Xr 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-399.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 7.8
EPSS exploit prediction: 3% (85th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-399
Affected product: Cisco Ios Xr
Published: 2016-08-23
Last modified: 2026-06-17

Description

Memory leak in Cisco IOS XR 5.1.x through 5.1.3, 5.2.x through 5.2.5, and 5.3.x through 5.3.2 on ASR 9001 devices allows remote attackers to cause a denial of service (control-plane protocol outage) via crafted fragmented packets, aka Bug ID CSCux26791.

Frequently asked questions

What is CVE-2016-6355?: Memory leak in Cisco IOS XR 5.1.x through 5.1.3, 5.2.x through 5.2.5, and 5.3.x through 5.3.2 on ASR 9001 devices allows remote attackers to cause a denial of service (control-plane protocol outage) via crafted fragmented packets, aka Bug ID CSCux26791.
How severe is CVE-2016-6355?: CVE-2016-6355 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 none, integrity none, and availability high.
Is CVE-2016-6355 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-6355?: CVE-2016-6355 primarily affects Cisco Ios Xr. In total, 14 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-6355?: 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-2016-6355 published?: CVE-2016-6355 was published on 2016-08-23 and last updated on 2026-06-17.

References

Affected products (14)

cpe:2.3:o:cisco:ios_xr:5.1.0:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:5.1.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:5.1.1.k9sec:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:5.1.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:5.1.3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:5.2.0:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:5.2.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:5.2.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:5.2.3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:5.2.4:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:5.2.5:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:5.3.0:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:5.3.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:5.3.2:*:*:*:*:*:*:*

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