How severe is CVE-2009-2056?

CVE-2009-2056 has a CVSS 2.0 base score of 3.3, rated low severity.

Is CVE-2009-2056 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (68th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-2056?

CVE-2009-2056 primarily affects Cisco Ios Xr. In total, 33 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-2056?

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

When was CVE-2009-2056 published?

CVE-2009-2056 was published on 2009-08-21 and last updated on 2026-06-16.

CVE-2009-2056

CVE-2009-2056 is a low-severity vulnerability in Cisco Ios Xr with a CVSS 2.0 base score of 3.3. 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-264.

Key facts

Severity: Low (CVSS 2.0 base score 3.3)
EPSS exploit prediction: 1% (68th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-264
Affected product: Cisco Ios Xr
Published: 2009-08-21
Last modified: 2026-06-16

Description

Cisco IOS XR 3.8.1 and earlier allows remote authenticated users to cause a denial of service (process crash) via vectors involving a BGP UPDATE message with many AS numbers prepended to the AS path.

Frequently asked questions

What is CVE-2009-2056?: Cisco IOS XR 3.8.1 and earlier allows remote authenticated users to cause a denial of service (process crash) via vectors involving a BGP UPDATE message with many AS numbers prepended to the AS path.
How severe is CVE-2009-2056?: CVE-2009-2056 has a CVSS 2.0 base score of 3.3, rated low severity.
Is CVE-2009-2056 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (68th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-2056?: CVE-2009-2056 primarily affects Cisco Ios Xr. In total, 33 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-2056?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-2056 published?: CVE-2009-2056 was published on 2009-08-21 and last updated on 2026-06-16.

References

Affected products (33)

cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.0:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.0.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.1.0:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.2.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.2.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.2.3:*:crs-1:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.2.3:*:prp:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.2.4:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.2.50:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.4:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.4.0:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.4.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.4.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.4.3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.5:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.5.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.5.3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.5.4:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.6:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.6.0:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.6.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.6.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.6.3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.7:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.7.0:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.7.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.7.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.7.3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:3.8.0:*:*:*:*:*:*:*

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