CISA KEV High Memory corruption

CVE-2025-20352 — Cisco IOS and IOS XE Software SNMP Denial of Service and Remote Code Execution Vulnerability

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.

Published Sep 24, 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

High

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 · Sep 29, 2025 Proofs of concept on GitHub · 2

How the score was calculated

Confirmed exploitation (CISA KEV)+35
Public exploit/PoC (github)+6
EPSS 40.2% (30-day exploitation probability)+15
Technical severity (high)+6

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 Sep 29, 2025

EPSS FIRST

40.17%

ahead of 99% of scored CVEs · Oct 14, 2026

Affects

Cisco

Cisco IOS XE Catalyst SD-WAN and 1 more

CVSS base

7.7

High · 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

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.

Documented mitigation — sec.cloudapps.cisco.com (NIST National Vulnerability Database)

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: Oct 20, 2025 — passed 360 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.

Identify exposed assets running the affected vendor/product/version combinations (Cisco Cisco IOS XE Catalyst SD-WAN, Cisco Cisco IOS XE Software).
Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
Apply the documented mitigations until a definitive fix is available.
EPSS ahead of 99% of scored CVEs: prioritize it in the patch queue.
Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Cisco	Cisco IOS XE Catalyst SD-WAN	version 16.11.1aversion 16.9.4version 16.10.1version 16.10.2version 16.10.3version 16.10.3aversion 16.10.3bversion 16.10.4 and 13 more version 16.10.5version 16.10.6version 16.9.3version 16.12.1bversion 16.12.1dversion 16.12.1eversion 16.12.2rversion 16.12.3version 16.12.4version 16.12.4aversion 16.12.5version 16.9.2version 16.9.1	Vulnerable	CVE Program (cve.org) e CISA ADP
Cisco	Cisco IOS XE Software	version 17.15.2version 17.15.1aversion 17.15.1bversion 17.15.1xversion 17.15.1zversion 17.15.3version 17.15.2cversion 17.15.2a and 271 more version 17.15.1yversion 17.15.2bversion 17.15.3aversion 17.15.4version 17.15.3bversion 17.16.1version 17.16.1aversion 17.17.1version 17.18.1version 3.18.1cSPversion 3.18.2SPversion 3.18.2aSPversion 3.18.3SPversion 3.18.4SPversion 3.18.3aSPversion 3.18.3bSPversion 3.18.5SPversion 3.18.6SPversion 3.18.7SPversion 3.18.8aSPversion 3.18.9SPversion 3.9.0Eversion 3.9.1Eversion 3.9.2Eversion 16.6.1version 16.6.2version 16.6.3version 16.6.4version 16.6.5version 16.6.4aversion 16.6.5aversion 16.6.6version 16.6.7version 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 16.8.1sversion 16.8.1cversion 16.8.1dversion 16.8.2version 16.8.1eversion 16.8.3version 16.9.1version 16.9.2version 16.9.1aversion 16.9.1bversion 16.9.1sversion 16.9.3version 16.9.4version 16.9.3aversion 16.9.5version 16.9.5fversion 16.9.6version 16.9.7version 16.9.8version 16.10.1version 16.10.1aversion 16.10.1bversion 16.10.1sversion 16.10.1cversion 16.10.1eversion 16.10.1dversion 16.10.2version 16.10.1fversion 16.10.1gversion 16.10.3version 3.10.0Eversion 3.10.1Eversion 3.10.0cEversion 3.10.2Eversion 3.10.3Eversion 16.11.1version 16.11.1aversion 16.11.1bversion 16.11.2version 16.11.1sversion 16.12.1version 16.12.1sversion 16.12.1aversion 16.12.1cversion 16.12.1wversion 16.12.2version 16.12.1yversion 16.12.2aversion 16.12.3version 16.12.8version 16.12.2sversion 16.12.1xversion 16.12.1tversion 16.12.4version 16.12.3sversion 16.12.3aversion 16.12.4aversion 16.12.5version 16.12.6version 16.12.1z1version 16.12.5aversion 16.12.5bversion 16.12.1z2version 16.12.6aversion 16.12.7version 16.12.9version 16.12.10version 16.12.10aversion 16.12.11version 16.12.12version 16.12.13version 3.11.0Eversion 3.11.1Eversion 3.11.2Eversion 3.11.3Eversion 3.11.1aEversion 3.11.4Eversion 3.11.3aEversion 3.11.5Eversion 3.11.6Eversion 3.11.7Eversion 3.11.8Eversion 3.11.9Eversion 3.11.10Eversion 3.11.11Eversion 3.11.12Eversion 17.1.1version 17.1.1aversion 17.1.1sversion 17.1.1tversion 17.1.3version 17.2.1version 17.2.1rversion 17.2.1aversion 17.2.1vversion 17.2.2version 17.2.3version 17.3.1version 17.3.2version 17.3.3version 17.3.1aversion 17.3.1wversion 17.3.2aversion 17.3.1xversion 17.3.1zversion 17.3.4version 17.3.5version 17.3.4aversion 17.3.6version 17.3.4bversion 17.3.4cversion 17.3.5aversion 17.3.5bversion 17.3.7version 17.3.8version 17.3.8aversion 17.4.1version 17.4.2version 17.4.1aversion 17.4.1bversion 17.4.2aversion 17.5.1version 17.5.1aversion 17.6.1version 17.6.2version 17.6.1wversion 17.6.1aversion 17.6.1xversion 17.6.3version 17.6.1yversion 17.6.1zversion 17.6.3aversion 17.6.4version 17.6.1z1version 17.6.5version 17.6.6version 17.6.6aversion 17.6.5aversion 17.6.7version 17.6.8version 17.6.8aversion 17.7.1version 17.7.1aversion 17.7.1bversion 17.7.2version 17.10.1version 17.10.1aversion 17.10.1bversion 17.8.1version 17.8.1aversion 17.9.1version 17.9.1wversion 17.9.2version 17.9.1aversion 17.9.1xversion 17.9.1yversion 17.9.3version 17.9.2aversion 17.9.1x1version 17.9.3aversion 17.9.4version 17.9.1y1version 17.9.5version 17.9.4aversion 17.9.5aversion 17.9.5bversion 17.9.6version 17.9.6aversion 17.9.7version 17.9.5eversion 17.9.5fversion 17.9.7aversion 17.9.7bversion 17.11.1version 17.11.1aversion 17.12.1version 17.12.1wversion 17.12.1aversion 17.12.1xversion 17.12.2version 17.12.3version 17.12.2aversion 17.12.1yversion 17.12.1zversion 17.12.4version 17.12.3aversion 17.12.1z1version 17.12.1z2version 17.12.4aversion 17.12.5version 17.12.4bversion 17.12.1z3version 17.12.5aversion 17.12.1z4version 17.12.5bversion 17.12.5cversion 17.13.1version 17.13.1aversion 17.14.1version 17.14.1aversion 17.15.1version 17.15.1wversion 3.5.0Eversion 3.5.1Eversion 3.5.2Eversion 3.5.3Eversion 3.6.0Eversion 3.6.1Eversion 3.6.2aEversion 3.6.2Eversion 3.6.3Eversion 3.6.4Eversion 3.6.5Eversion 3.6.6Eversion 3.6.5aEversion 3.6.7Eversion 3.6.8Eversion 3.6.7bEversion 3.6.9Eversion 3.6.10Eversion 3.14.0Sversion 3.14.1Sversion 3.14.2Sversion 3.14.3Sversion 3.14.4Sversion 3.15.0S	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

Changed

Confidentiality

None

Integrity

None

Availability

High

Every base score collected

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

Score	Version	Severity	Expl.	Impact	Scored by
7.7	CVSS 3.1	High	3.1	4.0	psirt@cisco.com via NIST National Vulnerability Database
7.7	CVSS 3.1	High	—	—	GitHub, Inc. via GitHub Security Advisories
7.7	CVSS 3.1	High	—	—	cisco via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H (score shown at the top: psirt@cisco.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-121 · Stack-based Buffer Overflow

Other CVEs with this weakness →

CISA KEV details CISA

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

Listed

Sep 29, 2025

Federal deadline

Oct 20, 2025

passed 360 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.

Proofs of concept on GitHub

CVE-2025-20352 SNMP Exposure Check (onesixtyone + parser) ★ 7 Sep 25, 2025
CVE-2025-20352 Research writeup ★ 0 Jul 21, 2026

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 40.17%

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).
Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Hunt retroactively in logs from before Sep 29, 2025 (KEV listing): exploitation may have started earlier.

web/proxy/WAF logsnetwork IDS/IPSendpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

2026
Affected products added · cisco/ios, cisco/cisco ios xe software, cisco/cisco ios xe catalyst sd-wan
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
Fix documented
Oct 13, 2026 · NIST National Vulnerability Database
Affected products added · cisco/ios xe sd-wan, cisco/ios xe, cisco/ios
Oct 13, 2026 · NIST National Vulnerability Database
CVSS changed · 7.7
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
Sep 28, 2025 · CISA
CVE published
Sep 24, 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

4 on the record

sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snmp-x4LPhte
Mitigation, Vendor Advisory, NIST National Vulnerability Database
www.cisa.gov/known-exploited-vulnerabilities-catalog
US Government Resource, NIST National Vulnerability Database
github.com/advisories/GHSA-c924-mch4-p3p3
GitHub Security Advisories
nvd.nist.gov/vuln/detail/CVE-2025-20352
GitHub Security Advisories

Elsewhere on this site

Cisco
every CVE for this vendor

2025-09
what else CISA listed that month

Memory corruption
same class

CWE-121
other pages naming this weakness

Related CVEs (same products)

Medium CVE-2026-20311 Cisco IOS XE Software Web UI Denial of Service Vulnerability Aug 5, 2026
Medium CVE-2026-20308 Cisco IOS XE Software Web-Based Management Interface Vulnerability Aug 5, 2026
High CVE-2026-20301 Cisco IOS Software and IOS XE Software Extensible Messaging Client Protocol Denial of Service Vulnerability Aug 5, 2026
High CVE-2026-20273 Cisco IOS XE Software Security Hardening Release Aug 5, 2026
Critical CVE-2026-20272 Cisco IOS XE Software Security Hardening Release Aug 5, 2026
High CVE-2026-20271 Cisco IOS XE Software Security Hardening Release 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 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-2025-20352 is "Cisco IOS and IOS XE Software SNMP Denial of Service and Remote Code Execution Vulnerability", rated High. It affects Cisco IOS XE Catalyst SD-WAN (Cisco); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 7.7 describes technical severity. EPSS 40.17% 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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