Cisco IOS XR is a widely deployed network OS; flaws can disrupt core networking and affect large organizations.
CVE-2026-20275
Cisco IOS XR incorrect-calculation flaws risk service disruption and privilege bypass.
Is CVE-2026-20275 being exploited?
Not confirmed. CVE-2026-20275 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.19% probability of exploitation in the next 30 days.
How severe is CVE-2026-20275?
CVE-2026-20275 is rated High with a CVSS score of 8.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-20275?
Yes. A fix has been recorded for CVE-2026-20275. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-20275 affect?
CVE-2026-20275 affects Cisco IOS XR Software. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-20275?
Apply Cisco IOS XR hardening releases per advisory immediately.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Incorrect calculations can be exploited to cause denial-of-service, bypass security checks, or achieve privilege escalation on IOS XR devices.
Immediate action required
- affected6.5.29
- affected7.0.1
- affected6.5.26
- affected6.5.25
- affected6.5.28
- affected6.5.90
- affected7.1.1
- affected7.0.90
- affected6.7.1
- affected7.0.2
- affected7.1.15
- affected7.2.1
- affected7.1.2
- affected6.7.2
- affected7.0.11
- affected7.0.12
- affected7.0.14
- affected7.1.25
- affected7.2.12
- affected7.3.1
- affected7.1.3
- affected6.7.3
- affected7.4.1
- affected7.2.2
- affected6.7.4
- affected6.5.31
- affected7.3.15
- affected7.3.16
- affected6.8.1
- affected7.4.15
- affected6.5.32
- affected7.3.2
- affected7.5.1
- affected7.4.16
- affected7.3.27
- affected7.6.1
- affected7.5.2
- affected7.8.1
- affected7.6.15
- affected7.5.12
- affected7.8.12
- affected7.3.3
- affected7.7.1
- affected6.8.2
- affected7.3.4
- affected7.4.2
- affected6.7.35
- affected6.9.1
- affected7.6.2
- affected7.5.3
- affected7.7.2
- affected6.9.2
- affected7.9.1
- affected7.10.1
- affected7.8.2
- affected7.5.4
- affected6.5.33
- affected7.8.22
- affected7.7.21
- affected7.9.2
- affected7.3.5
- affected7.5.5
- affected7.11.1
- affected7.9.21
- affected7.10.2
- affected24.1.1
- affected7.6.3
- affected7.3.6
- affected7.5.52
- affected7.11.2
- affected24.2.1
- affected24.1.2
- affected24.2.11
- affected24.3.1
- affected24.4.1
- affected24.2.2
- affected7.8.23
- affected7.11.21
- affected24.2.20
- affected24.3.2
- affected24.4.10
- affected6.5.35
- affected25.1.1
- affected24.4.2
- affected24.3.20
- affected24.4.15
- affected25.2.1
- affected6.5.351
- affected25.1.2
- affected24.3.30
- affected25.3.1
- affected6.5.352
- affected24.4.30
- affected24.2.21
- affected25.4.1
- affected25.2.2
- affected25.2.15
- affected7.2.0
- affected7.0.0
- affected25.2.30
- affected6.5.353
- affected26.1.1
- affected25.1.30
- affected25.3.15
- affected26.2.100
- affected25.4.2
- affected26.2.1
- affected25.4.30
- affected26.1.2
- affected25.4.201
- affected26.2.101
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.