Cisco IOS XR Software Security Hardening Release: September 2026
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 software hardening releases that address multiple internally discovered vulnerabilities. These vulnerabilities were found during internal testing and are not known to be actively exploited. To assist customers in patching and streamline the disclosure process, Cisco has grouped these issues by their underlying vulnerability class — Common Weakness Enumeration (CWE) — and assigned a single Common Vulnerabilities and Exposures identifier (CVE ID) to each CWE grouping. Cisco has released software updates that address these vulnerabilities. There are no workarounds that address these vulnerabilities. This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-iosxr-qg64NcM Security Impact Rating: Critical CVE: CVE-2026-20274,CVE-2026-20275,CVE-2026-20276,CVE-2026-20277,CVE-2026-20278,CVE-2026-20279,CVE-2026-20280
CSIRTS triage
- What
- Multiple internally discovered vulnerabilities grouped by CWE and assigned single CVE identifiers, addressed through security hardening releases.
- Who is affected
- Cisco IOS XR Software deployments across all affected versions.
- Urgency
- Critical; no active exploitation known but comprehensive internal security review identified multiple high-risk flaws requiring immediate patching.
- Action
- Apply Cisco security hardening releases addressing CVE-2026-20274 through CVE-2026-20280 without delay.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-20274 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-20275 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-20276 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-20277 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-20278 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-20279 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-20280 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
- high[NEW] [high] Cisco IOS XR: Multiple vulnerabilities enable unspecified attackcert-bund
- unknownCisco Products Multiple Vulnerabilitieshkcert
- highCVE-2026-20280: As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS…nvd
- criticalCVE-2026-20279: As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS…nvd
- highCVE-2026-20278: As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS…nvd
- highCVE-2026-20277: As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS…nvd
- highCVE-2026-20276: As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS…nvd
- highCVE-2026-20275: As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS…nvd
- criticalCVE-2026-20274: As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS…nvd
- criticalCisco Advance Notification for Publication of September 2, 2026, Security Advisoriescisco-psirt
Recent advisories for Cisco IOS XR
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
- high[NEW] [high] Cisco IOS XR: Multiple vulnerabilities enable unspecified attackcert-bund · 2026-09-03
- highCVE-2026-20280: As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS…nvd · 2026-09-02
- criticalCVE-2026-20279: As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS…nvd · 2026-09-02
- highCVE-2026-20278: As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS…nvd · 2026-09-02
- highCVE-2026-20277: As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS…nvd · 2026-09-02
- highCVE-2026-20276: As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS…nvd · 2026-09-02
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