CVE Intelligence
CISA KEV Critical Injection exploit reference

CVE-2025-20281 — Cisco Identity Services Engine Injection Vulnerability

A vulnerability in a specific API of Cisco ISE and Cisco ISE-PIC could allow an unauthenticated, remote attacker to execute arbitrary code on the underlying operating system as root. The attacker does not require any valid credentials to exploit this vulnerability. This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by submitting a crafted API request. A successful exploit could allow the attacker to obtain root privileges on an affected device.

Published Jun 25, 2025 · Updated Oct 13, 2026 · Sources: CISA Known Exploited Vulnerabilities, NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: cisco

Who exploits it and how urgent it is

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

CISA KEV · Jul 28, 2025 Detection templates (Nuclei) · 1Proofs of concept on GitHub · 3
How the score was calculated
  • Confirmed exploitation (CISA KEV)+35
  • Public exploit/PoC (nuclei, github)+10
  • EPSS 97.6% (30-day exploitation probability)+15
  • Technical severity (critical)+10
  • Automatable exploitation (SSVC)+3

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
Confirmed
CISA KEV, listed Jul 28, 2025
EPSS FIRST
97.6%
ahead of 100% of scored CVEs · Oct 14, 2026
Affects
Cisco
Cisco Identity Services Engine Software and 2 more
CVSS base
10.0
Critical · 3 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
Active
none · proof-of-concept · active
Automatable
Yes
can an attacker script the kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component

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.

CISA required action CISA

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

US federal deadline: Aug 18, 2025 — passed 423 day(s) ago

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 Cisco Identity Services Engine Software, Cisco Identity Services Engine, Cisco Identity Services Engine Passive Identity Connector).
  2. Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
  3. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  4. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  5. EPSS ahead of 100% of scored CVEs: prioritize it in the patch queue.
  6. 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 Cisco Identity Services Engine Software version 3.3 Patch 6version 3.3 Patch 5version 3.4 Patch 1version 3.3 Patch 4version 3.4.0version 3.3 Patch 3version 3.3 Patch 1version 3.3 Patch 2
and 1 more version 3.3.0
Vulnerable CVE Program (cve.org) e CISA ADP
Cisco Identity Services Engine version 3.3.0-patch1version 3.3.0version 3.3.0-patch2version 3.3.0-patch3version 3.3.0-patch4version 3.3.0-patch5version 3.3.0-patch6version 3.4.0
and 1 more version 3.4.0-patch1
Vulnerable NIST National Vulnerability Database
Cisco Identity Services Engine Passive Identity Connector version 3.3.0version 3.3.0-patch1version 3.4.0-patch1version 3.4.0version 3.3.0-patch6version 3.3.0-patch5version 3.3.0-patch4version 3.3.0-patch3
and 1 more version 3.3.0-patch2
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
Changed
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
10.0 CVSS 3.1 Critical 3.9 6.0 psirt@cisco.com via NIST National Vulnerability Database
10.0 CVSS 3.1 Critical — — cisco via CVE Program (cve.org) e CISA ADP
9.8 CVSS 3.1 Critical — — GitHub, Inc. via GitHub Security Advisories
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H (score shown at the top: psirt@cisco.com)
Sources assign different scores within the same severity band. For prioritization we use 10.0 (psirt@cisco.com via NIST National Vulnerability Database) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-74 · Injection

Other CVEs with this weakness →

CISA KEV details CISA

CISA lists a CVE once it has evidence of exploitation against real targets.

Listed
Jul 28, 2025
Federal deadline
Aug 18, 2025
passed 423 day(s) ago
Ransomware use
Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.

Public exploits, PoCs and detection templates

Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.

Detection templates (Nuclei)
Proofs of concept on GitHub

Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.

EPSS over time FIRST

Oct 12, 2026 → Oct 14, 2026 · 3 reading(s) · max 97.60%

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.
  • Hunt retroactively in logs from before Jul 28, 2025 (KEV listing): exploitation may have started earlier.
web/proxy/WAF logsnetwork IDS/IPSapplication logsendpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · cisco/cisco identity services engine software
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • Affected products added · cisco/identity services engine, cisco/identity services engine passive identity connector
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVSS changed · 10.0
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Analyzed
    Oct 13, 2026 · NIST National Vulnerability Database
  • Added to CISA KEV (detected)
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • Record created in this database
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • 2025
  • Added to CISA KEV catalog
    Jul 27, 2025 · CISA
  • CVE published
    Jun 25, 2025 · cisco

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 13, 2026 – Oct 13, 2026
  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

5 on the record

Elsewhere on this site

Cisco
every CVE for this vendor
2025-07
what else CISA listed that month
Injection
same class
CWE-74
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-76460 Cisco Identity Services Engine Incorrect Use of Privileged APIs Vulnerability KEV 29d
  • CVE-2026-76450 A vulnerability in Cisco Identity Services Engine (ISE) and Cisco ISE Passive Identity… 29d
  • CVE-2026-76449 SQL Injection in Cisco Identity Services Engine 29d
  • CVE-2026-76451 A vulnerability in Cisco Identity Services Engine (ISE) and Cisco ISE Passive Identity… 29d
  • CVE-2026-76446 XML External Entity (XXE) in Cisco Identity Services Engine 29d
  • CVE-2026-76448 SQL Injection in Cisco Identity Services Engine 29d

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 fixed version, patch or mitigation documented.
  • 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-2025-20281 is "Cisco Identity Services Engine Injection Vulnerability", rated Critical. It affects Cisco Identity Services Engine Software (Cisco); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 10.0 describes technical severity. EPSS 97.60% estimates the probability of exploitation in 30 days; neither replaces your asset context. 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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