Cisco IOS XE Software Security Hardening Release: August 2026

criticalCVE-2026-20267 CVE-2026-20268 CVE-2026-20269 CVE-2026-20270 CVE-2026-20271 CVE-2026-20272

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XE 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). 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-iosxe-V8NMuMZJ Security Impact Rating: Critical CVE: CVE-2026-20267,CVE-2026-20268,CVE-2026-20269,CVE-2026-20270,CVE-2026-20271,CVE-2026-20272,CVE-2026-20273

CSIRTS triage

vendor: Cisco product: IOS XE Software Remote code execution Authentication bypass Privilege escalation Information disclosure Denial of service

What: Multiple internally discovered vulnerabilities in IOS XE Software grouped by Common Weakness Enumeration class.
Who is affected: All versions of Cisco IOS XE Software are affected.
Urgency: Critical severity; no active exploitation known but internal testing identified multiple vulnerability classes requiring immediate patching.
Action: Apply Cisco security updates for IOS XE Software immediately; no workarounds available.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Cisco Security Advisories (INTL · vendor-psirt · site)
Severity: critical
Published: 2026-08-05
Exploitation: Not in CISA KEV at last sync

Original advisory: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-iosxe-V8NMuMZJ?vs_f=Cisco%20Security%20Advisory%26vs_cat=Security%20Intelligence%26vs_type=RSS%26vs_p=Cisco%20IOS%20XE%20Software%20Security%20Hardening%20Release:%20August%202026%26vs_k=1

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-202670.26% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 18% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-202680.28% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 21% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-202690.28% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 21% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-202700.28% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 21% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-202710.28% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 20% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-202720.41% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 34% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-202730.28% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 20% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-20267	coverage & exploitation status	NVD · CVE.org
CVE-2026-20268	coverage & exploitation status	NVD · CVE.org
CVE-2026-20269	coverage & exploitation status	NVD · CVE.org
CVE-2026-20270	coverage & exploitation status	NVD · CVE.org
CVE-2026-20271	coverage & exploitation status	NVD · CVE.org
CVE-2026-20272	coverage & exploitation status	NVD · CVE.org
CVE-2026-20273	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

Recent advisories for Cisco IOS XE

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.

unknownMultiple vulnerabilities in Cisco IOS XE (August 25, 2026)cert-fr-avis · 2026-08-25
unknownNCSC-2026-0279 [1.00] [M/H] Vulnerabilities patched in Cisco IOS XE Softwarencsc-nl · 2026-08-07
high[NEW] [high] Cisco IOS XE: Multiple Vulnerabilitiescert-bund · 2026-08-06
mediumCVE-2026-20311: A vulnerability in the web-based management interface of Cisco IOS XE Software could allow an …nvd · 2026-08-05
mediumCVE-2026-20308: A vulnerability in the web-based management interface of Cisco IOS XE Software could allow an …nvd · 2026-08-05
highCVE-2026-20301: A vulnerability in the Extensible Messaging Client Protocol (XMCP), also referred to as the Ex…nvd · 2026-08-05