CVE-2025-20352
HighExploitedPublic exploitA vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS Software and Cisco IOS XE Software could allow the following: An authenticated, remote attacker with low privileges could cause a denial of service (DoS) condition on an affected device that…
Published Sep 24, 2025 · Updated Sep 26, 2026
Key Facts
Patch immediately- CVE-2025-20352 is a high-severity vulnerability (CVSS 7.7 v3.1) affecting IOS (Cisco), IOS Xe (Cisco), IOS Xe SD-WAN (Cisco) and 2 more products.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Sep 24, 2025. Public exploit code is available.
- EPSS estimates a 40% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
7.7
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
EPSS (30-day exploit likelihood)
40%
Higher than 98.6% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2025-20352 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS Software and Cisco IOS XE Software could allow the following: An authenticated, remote attacker with low privileges could cause a denial of service (DoS) condition on an affected device that is running Cisco IOS Software or Cisco IOS XE Software. To cause the DoS, the attacker must have the SNMPv2c or earlier read-only community string or valid SNMPv3 user credentials. An authenticated, remote attacker with high privileges could execute code as the root user on an affected device that is running Cisco IOS XE Software. To execute code as the root user, the attacker must have the SNMPv1 or v2c read-only community string or valid SNMPv3 user credentials and administrative or privilege 15 credentials on the affected device. An attacker could exploit this vulnerability by sending a crafted SNMP packet to an affected device over IPv4 or IPv6 networks. This vulnerability is due to a stack overflow condition in the SNMP subsystem of the affected software. A successful exploit could allow a low-privileged attacker to cause the affected system to reload, resulting in a DoS condition, or allow a high-privileged attacker to execute arbitrary code as the root user and obtain full control of the affected system. Note: This vulnerability affects all versions of SNMP.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Sep 29, 2025 | Oct 20, 2025 | Not reported |
| Industry KEV feed | Sep 24, 2025 | Oct 20, 2025 | Not reported |
| CIRCL KEV | Sep 29, 2025 | Oct 20, 2025 | Not reported |
| ENISA EUVD | Sep 29, 2025 | n/a | Not reported |
Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Affected Products
1,099 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| IOSCisco | 12.2\(33\)sxi, 12.2\(33\)sxi1, 12.2\(33\)sxi10, 12.2\(33\)sxi11, 12.2\(33\)sxi12, 12.2\(33\)sxi13, 12.2\(33\)sxi14, 12.2\(33\)sxi2 | n/a |
| IOS XeCisco | 16.10.1, 16.10.1a, 16.10.1b, 16.10.1c, 16.10.1d, 16.10.1e, 16.10.1f, 16.10.1g | n/a |
| IOS Xe SD-WANCisco | 16.10.1, 16.10.2, 16.10.3, 16.10.3a, 16.10.3b, 16.10.4, 16.10.5, 16.10.6 | n/a |
| Cisco IOS XE Catalyst SD-WAN | >= 16.9.1 | n/a |
| Cisco IOS XE Software | >= 3.5.0E | n/a |
Timeline
Publicly disclosed
Sep 24, 2025
Added to Industry KEV feed
Sep 24, 2025
Added to CISA KEV
Sep 29, 2025
Added to CIRCL KEV
Sep 29, 2025
Added to ENISA EUVD
Sep 29, 2025
Last updated
Sep 26, 2026
Weakness Type
- CWE-121 Stack-based Buffer Overflow
References
- advisorycisco-sa-snmp-x4LPhte
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS Software and Cisco IOS XE Software could allow the following: An authenticated, remote attacker with low privileges could cause a denial of service (DoS) condition on an affected device that is running Cisco IOS Software or Cisco I…
Affected: IOS (Cisco) versions 12.2\(33\)sxi, 12.2\(33\)sxi1, 12.2\(33\)sxi10, 12.2\(33\)sxi11, 12.2\(33\)sxi12, 12.2\(33\)sxi13, 12.2\(33\)sxi14, 12.2\(33\)sxi2; IOS Xe (Cisco) versions 16.10.1, 16.10.1a, 16.10.1b, 16.10.1c, 16.10.1d, 16.10.1e, 16.10.1f, 16.10.1g; IOS Xe SD-WAN (Cisco) versions 16.10.1, 16.10.2, 16.10.3, 16.10.3a, 16.10.3b, 16.10.4, 16.10.5, 16.10.6, among others. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Sep 24, 2025.
Yes. It was added on Sep 29, 2025 with a federal remediation due date of Oct 20, 2025.
Public exploit code is available.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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