CVE Intelligence
Medium

CVE-2026-20172 — Cisco Enterprise Chat and Email Lite Agent File Upload Vulnerability

A vulnerability in the Lite Agent feature of Cisco Enterprise Chat and Email (ECE) could allow an authenticated, remote attacker to conduct browser-based attacks. To exploit this vulnerability, the attacker must have valid credentials for a user account with at least the role of Agent. This vulnerability is due to inadequate validation of file contents during file upload operations. An attacker could exploit this vulnerability by uploading a file that contains malicious scripts or HTML code, which the application could make available to other users to access. A successful exploit could allow the attacker to execute the contents of that file in the browser of a user and conduct browser-based attacks. 

Published May 6, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · 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.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.1% (30-day exploitation probability)+0
  • Technical severity (medium)+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
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.13%
ahead of 2% of scored CVEs · Oct 14, 2026
Affects
Cisco
Enterprise Chat And Email
CVSS base
4.3
Medium · 2 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
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Partial
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.

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 Enterprise Chat And Email).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Cisco Enterprise Chat And Email version 12.6(1)_ES6_ET1version 12.6(1)_ES5_ET3version 12.6(1)_ES6_ET3version 12.6(1)_ES7_ET1version 12.6(1)_ES8_ET1version 12.6(1)_ES1_ET2version 12.6(1)_ES2_ET5version 12.6(1)_ES3_ET3
and 91 more version 12.6(1)_ES4_ET2version 12.6(1)_ES8version 12.6(1)_ES7version 12.6(1)_ES6_ET2version 12.5(1)_ES8version 12.5(1)_ES8_ET1version 12.6(1)_ES6version 12.6(1)_ES5_ET2version 12.6(1)_ES5_ET1version 12.6(1)_ES5version 12.6(1)_ES4_ET1version 12.5(1)_ES7version 12.6(1)_ES4version 12.6_ES3_ET2version 12.5(1)_ES6version 12.6_ES3_ET1version 11.6(1)_ES12_ET1version 12.6(1)_ES10version 12.5(1)_ES10version 15.0(1)ES202511_ET1version 12.6(1)_ES12_ET1version 15.0(1)ES202511version 12.6(1)_ES12version 12.6(1)_ES11_ET2version 12.6(1)_ES11_ET1version 15.0(1)ES202508version 15.0(1)_ET1version 12.6(1)_ES11version 15.0(1)version 12.6(1)_ES10_ET1version 12.6(1)_ES3version 12.6(1)_ES9_ET3version 12.6(1)_ES9_ET2version 12.5(1)_ES9version 12.6(1)_ES9_ET1version 12.6(1)_ES9version 12.6(1)_ES8_ET2version 12.5(1)_ES7_ET1version 12.5(1)_ES4_ET2version 12.5(1)_ES6_ET1version 12.5(1)_ES5_ET2version 12.5(1)_ES3_ET3version 12.0(1)_ES3version 12.0(1)_ES2version 11.5(1)version 12.6(1)version 12.5(1)_ES3version 12.0(1)version 12.0(1)_ES1version 11.6(1)_ES10version 11.6(1)_ES9aversion 11.6(1)_ES2version 12.0(1)_ES5version 12.0(1)_ES4version 11.6(1)_ES11version 11.6(1)_ES7version 12.5(1)_ES3_ET1version 12.5(1)version 12.5(1)_ET1version 11.6(1)_ES5version 11.6(1)_ES6version 12.0(1)_ES6_ET1version 11.6(1)_ES9version 12.0(1)_ES5aversion 11.6(1)_ES8version 12.0(1)_ES6version 11.6(1)_ES4version 12.5(1)_ES4_ET1version 12.6_ES2_ET4version 12.5(1)_ES5_ET1version 12.0(1)_ES7_ET1version 12.6_ES2_ET3version 12.0(1)_ES7version 12.6_ES2_ET2version 12.5(1)_ES5version 12.6_ES2_ET1version 12.6(1)_ES2version 12.6(1)_ES1_ET1version 12.0(1)_ES6_ET3version 11.6(1)_ES3version 12.6(1)_ET3version 11.6(1)_ES12version 12.5(1)_ES4version 12.6(1)_ES1version 12.0(1)_ES6_ET2version 12.5(1)_ES3_ET2version 12.6(1)_ET2version 12.5(1)_ES1version 11.6(1)version 12.6(1)_ET1version 12.5(1)_ES2
Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

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

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

Every base score collected

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

ScoreVersionSeverityExpl.ImpactScored by
4.3 CVSS 3.1 Medium 2.8 1.4 psirt@cisco.com via NIST National Vulnerability Database
4.3 CVSS 3.1 Medium — — cisco via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N (score shown at the top: psirt@cisco.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-646

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.13%

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).
web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · cisco/cisco enterprise chat and email
    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
  • CVSS changed · 4.3
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Awaiting Analysis
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVE published
    May 6, 2026 · cisco

Source activity

Repeated readings are counted rather than listed.

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

References

1 on the record

Elsewhere on this site

Cisco
every CVE for this vendor
CWE-646
other pages naming this weakness

Related CVEs (same products)

  • CVE-2023-44487 HTTP/2 Rapid Reset Attack Vulnerability KEV Oct 10, 2023
  • CVE-2021-44228 Apache Log4j2 Remote Code Execution Vulnerability KEV Dec 10, 2021

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-2026-20172 is "Cisco Enterprise Chat and Email Lite Agent File Upload Vulnerability", rated Medium. It affects Enterprise Chat And Email (Cisco); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 4.3 describes technical severity. EPSS 0.13% 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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