How severe is CVE-2026-20276?

CVE-2026-20276 has a CVSS 3.x base score of 8.6, 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-2026-20276 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-20276?

CVE-2026-20276 primarily affects Cisco Ios Xr. In total, 111 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-20276?

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-2026-20276 published?

CVE-2026-20276 was published on 2026-09-02 and last updated on 2026-09-18.

CVE-2026-20276

CVE-2026-20276 is a high-severity vulnerability in Cisco Ios Xr with a CVSS 3.x base score of 8.6. 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-691.

Key facts

Severity: High (CVSS 3.x base score 8.6)
EPSS exploit prediction: 0% (19th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-691
Affected product: Cisco Ios Xr
Published: 2026-09-02
Last modified: 2026-09-18

Description

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XR Software engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20276 are related to insufficient control flow management issues that are grouped under the Common Weakness Enumeration (CWE) CWE-691.

Frequently asked questions

What is CVE-2026-20276?: As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XR Software engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20276 are related to insufficient control flow management issues that are grouped under the Common Weakness Enumeration (CWE) CWE-691.
How severe is CVE-2026-20276?: CVE-2026-20276 has a CVSS 3.x base score of 8.6, 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-2026-20276 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-20276?: CVE-2026-20276 primarily affects Cisco Ios Xr. In total, 111 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-20276?: 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-2026-20276 published?: CVE-2026-20276 was published on 2026-09-02 and last updated on 2026-09-18.

References

Affected products (111)

cpe:2.3:o:cisco:ios_xr:6.5.25:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.5.26:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.5.28:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.5.29:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.5.31:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.5.32:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.5.33:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.5.35:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.5.90:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.5.351:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.5.352:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.5.353:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.7.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.7.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.7.3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.7.4:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.7.35:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.8.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.8.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.9.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.9.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.0.0:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.0.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.0.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.0.11:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.0.12:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.0.14:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.0.90:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.1.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.1.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.1.3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.1.15:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.1.25:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.2.0:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.2.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.2.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.2.12:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.3.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.3.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.3.3:*:*:*:*:*:*:*

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