CVE Intelligence
Critical Injection

CVE-2026-20272 — Injection in Cisco Ios Xe

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. The vulnerabilities tracked by CVE-2026-20272 are related to issues with improper neutralization of special elements that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-74.

Published Aug 5, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database · CNA: psirt@cisco.com

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • Technical severity (critical)+10

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
—
No EPSS score.
Affects
Cisco
Ios Xe
CVSS base
9.8
Critical · 1 source(s)

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Cisco Ios Xe).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  4. Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Cisco Ios Xe version 17.15.5aversion 26.1.1aversion 26.1.1version 17.18.3aversion 17.18.3version 17.18.2version 17.18.1zversion 17.18.1y
and 259 more version 17.18.1xversion 17.18.1wversion 17.18.1aversion 17.17.1version 17.16.1aversion 17.16.1version 17.15.7version 17.15.2version 17.15.5version 17.15.4s1version 17.15.4dversion 17.15.4cversion 17.15.4bversion 17.15.4aversion 17.15.4version 17.15.3bversion 17.15.3aversion 17.15.3version 17.15.2cversion 17.15.2bversion 17.15.2aversion 17.3.1xversion 17.3.1zversion 17.3.2version 17.3.2aversion 17.3.3version 17.3.3aversion 17.3.4version 17.3.4aversion 17.3.4bversion 17.3.4cversion 17.3.5version 17.3.5aversion 17.3.5bversion 17.3.6version 17.3.7version 17.3.8version 17.3.8aversion 17.4.1version 17.4.1aversion 17.4.1bversion 17.4.1cversion 17.4.2version 17.4.2aversion 17.5.1version 17.5.1aversion 17.6.1version 17.6.1aversion 17.6.1xversion 17.6.1zversion 17.6.1z1version 17.6.2version 17.6.3version 17.6.3aversion 17.6.4version 17.6.5version 17.6.5aversion 17.6.6version 17.6.6aversion 17.6.7version 17.6.8version 17.6.8aversion 17.7.1version 17.7.1aversion 17.7.1bversion 17.7.2version 17.8.1version 17.8.1aversion 17.9.1version 17.9.1aversion 17.9.1wversion 17.9.1xversion 17.9.1x1version 17.9.1yversion 17.9.1y1version 17.9.2version 17.9.2aversion 17.9.3version 17.9.3aversion 17.9.4version 17.9.4aversion 17.9.5version 17.9.5aversion 17.9.5bversion 17.9.5cversion 17.9.5dversion 17.9.5eversion 17.9.5fversion 17.9.6version 17.9.6aversion 17.9.7version 17.9.7aversion 17.9.7bversion 17.9.8version 17.9.9version 17.10.1version 17.10.1aversion 17.10.1bversion 17.11.1version 17.11.1aversion 17.12.1version 17.12.1aversion 17.12.1wversion 17.12.1xversion 17.12.1yversion 17.12.1zversion 17.12.1z1version 17.12.1z2version 17.12.1z3version 17.12.1z4version 17.12.1z5version 17.12.1z6version 17.12.2version 17.12.2aversion 17.12.3version 17.12.3aversion 17.12.4version 17.12.4aversion 17.12.4bversion 17.12.5version 17.12.5aversion 17.12.5bversion 17.12.5cversion 17.12.5dversion 17.12.6version 17.12.6aversion 17.12.6bversion 17.12.7version 17.12.7aversion 17.12.7bversion 17.13.1version 17.13.1aversion 17.14.1version 17.14.1aversion 17.15.1version 17.15.1aversion 17.15.1bversion 17.15.1wversion 17.15.1xversion 17.15.1yversion 16.6.2version 16.6.3version 16.6.4version 16.6.4aversion 16.6.4sversion 16.6.5version 16.6.5aversion 16.6.5bversion 16.6.6version 16.6.7version 16.6.7aversion 16.6.8version 16.6.9version 16.6.10version 16.7.1version 16.7.1aversion 16.7.1bversion 16.7.2version 16.7.3version 16.7.4version 16.8.1version 16.8.1aversion 16.8.1bversion 16.8.1cversion 16.8.1dversion 16.8.1eversion 16.8.1sversion 16.8.2version 16.8.3version 16.9.1version 16.9.1aversion 16.9.1bversion 16.9.1cversion 16.9.1dversion 16.9.1sversion 16.9.2version 16.9.2aversion 16.9.2sversion 16.9.3version 16.9.3aversion 16.9.3hversion 16.9.3sversion 16.9.4version 16.9.4cversion 16.9.5version 16.9.5fversion 16.9.6version 16.9.7version 16.9.8version 16.9.8aversion 16.9.8bversion 16.10.1version 16.10.1aversion 16.10.1bversion 16.10.1cversion 16.10.1dversion 16.10.1eversion 16.10.1fversion 16.10.1gversion 16.10.1sversion 16.10.2version 16.10.3version 16.11.1version 16.11.1aversion 16.11.1bversion 16.11.1cversion 16.11.1sversion 16.11.2version 16.12.1version 16.12.1aversion 16.12.1cversion 16.12.1sversion 16.12.1tversion 16.12.1wversion 16.12.1xversion 16.12.1yversion 16.12.1zversion 16.12.1z1version 16.12.1z2version 16.12.2version 16.12.2aversion 16.12.2sversion 16.12.2tversion 16.12.3version 16.12.3aversion 16.12.3sversion 16.12.4version 16.12.4aversion 16.12.5version 16.12.5aversion 16.12.5bversion 16.12.6version 16.12.6aversion 16.12.7version 16.12.8version 16.12.9version 16.12.10version 16.12.10aversion 16.12.11version 16.12.12version 16.12.13version 16.12.14version 16.12.15version 16.12.16version 17.1.1version 17.1.1aversion 17.1.1sversion 17.1.1tversion 17.1.2version 17.1.3version 17.2.1version 17.2.1aversion 17.2.1rversion 17.2.1vversion 17.2.2version 17.2.3version 17.3.1version 17.3.1aversion 17.3.1w
Vulnerable NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
9.8 CVSS 3.1 Critical 3.9 5.9 psirt@cisco.com via NIST National Vulnerability Database
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: psirt@cisco.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-74 · Injection

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Look for parameters with command/query metacharacters and unexpected child processes of the service.
web/proxy/WAF logsnetwork IDS/IPSapplication logsendpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

  • 2026
  • Record published
    Oct 15, 2026
  • CVSS changed · 9.8
    Oct 15, 2026 · NIST National Vulnerability Database
  • Source status changed · → Modified
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVE published
    Aug 5, 2026 · psirt@cisco.com

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

2 on the record

Elsewhere on this site

Cisco
every CVE for this vendor
Injection
same class
CWE-74
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-20301 A vulnerability in the Extensible Messaging Client Protocol (XMCP), also referred to as… Aug 5, 2026
  • CVE-2026-20273 Improper Input Validation in Cisco Ios Xe Aug 5, 2026
  • CVE-2026-20271 As part of Cisco's ongoing commitment to proactive security and product quality, the… Aug 5, 2026
  • CVE-2026-20269 As part of Cisco's ongoing commitment to proactive security and product quality, the… Aug 5, 2026
  • CVE-2026-20270 As part of Cisco's ongoing commitment to proactive security and product quality, the… Aug 5, 2026
  • CVE-2026-20267 Improper Access Control in Cisco Ios Xe Aug 5, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No FIRST EPSS score.
  • No fixed version, patch or mitigation documented.
  • No CISA SSVC assessment.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-20272 is "Injection in Cisco Ios Xe", rated Critical. It affects Ios Xe (Cisco); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.8 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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