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IOS XE vulnerabilitiesAnd the versions its exploited flaws hit.

Product29 known exploited1,101 versions
The short answer

IOS XE is made by Cisco. We track 506 published vulnerabilities listed under that exact name, across 1,101 versions. 29 of them are on the list of flaws known to be exploited, the newest added on 29 September 2025. Cisco lists newer releases under their own names, such as Ios XE SD-WAN, so check those pages too.

Check your version

The most recent IOS XE flaw added to the known-exploited list is CVE-2025-20352, on 29 September 2025. We keep watching the known-exploited list.

Other names

Is IOS XE listed under other names? Yes.

Cisco also lists IOS XE under more specific names, such as Ios XE SD-WAN and Ios XE 3.4sg. Flaws listed only under those names are counted on their own pages, not here. If you run one of these, open its page for its own exploited flaws.

Versions

Which versions of IOS XE do the exploited flaws hit?

Each exploited flaw lists the versions it affects, usually as ranges. "16.12 to before 16.12.10a" means from 16.12 up to, but not including, 16.12.10a. Find your version, then patch.

  • CVE-2025-20352Exploited list, 29 Sep 2025

    Cisco IOS and IOS XE Software SNMP Denial of Service and Remote Code Execution Vulnerability

    3.5.0e3.5.0sq3.5.1e3.5.1sq3.5.2e3.5.2sq3.5.3e3.5.3sq
  • CVE-2023-20273Exploited list, 23 Oct 2023

    Cisco IOS XE Web UI Command Injection Vulnerability

    16.1.116.1.216.1.316.2.116.2.216.3.1a16.3.216.3.3
  • CVE-2021-1435Exploited list, 19 Oct 2023

    Cisco IOS XE Web UI Command Injection Vulnerability

    16.9.1a16.9.1b16.9.116.9.1c16.9.1d16.9.1s16.9.2a16.9.2
  • CVE-2023-20198Exploited list, 16 Oct 2023

    Cisco IOS XE Web UI Privilege Escalation Vulnerability

    16.12 to before 16.12.10a17.3 to before 17.3.8a17.6 to before 17.6.6a17.9 to before 17.9.4a
  • CVE-2023-44487Exploited list, 10 Oct 2023

    HTTP/2 Rapid Reset Attack Vulnerability

    before 17.15.1
  • CVE-2023-20109Exploited list, 10 Oct 2023

    Cisco IOS and IOS XE Group Encrypted Transport VPN Out-of-Bounds Write Vulnerability

    3.3.0sg3.3.1sg3.3.2sg3.4.0sg3.4.1sg3.4.2sg3.4.3sg3.4.4sg
  • CVE-2016-6415Exploited list, 19 May 2023

    Cisco IOS, IOS XR, and IOS XE IKEv1 Information Disclosure Vulnerability

    up to 3.18s
  • CVE-2017-6742Exploited list, 19 Apr 2023

    Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability

    2.2.0 to 3.17
  • CVE-2017-3881Exploited list, 25 Mar 2022

    Cisco IOS and IOS XE Remote Code Execution Vulnerability

    3.2sg to 3.9e
  • CVE-2017-6739Exploited list, 3 Mar 2022

    Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability

    2.2.0 to 3.17.0
  • CVE-2017-6740Exploited list, 3 Mar 2022

    Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability

    2.2.0 to 3.17
  • CVE-2017-6743Exploited list, 3 Mar 2022

    Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability

    2.2.0 to 3.17
  • CVE-2018-0151Exploited list, 3 Mar 2022

    Cisco IOS Software and Cisco IOS XE Software Quality of Service Remote Code Execution Vulnerability

    16.5.1
  • CVE-2018-0155Exploited list, 3 Mar 2022

    Cisco Catalyst Bidirectional Forwarding Detection Denial-of-Service Vulnerability

    3.6(2)e
  • CVE-2018-0156Exploited list, 3 Mar 2022

    Cisco IOS Software and Cisco IOS XE Software Smart Install Denial-of-Service Vulnerability

    15.2(2a)ja15.2(2)e4
  • CVE-2018-0158Exploited list, 3 Mar 2022

    Cisco IOS and XE Software Internet Key Exchange Memory Leak Vulnerability

    15.5(3)s1.115.5(3)s1.215.5(3)s1.415.5(3)s1.515.5(3)s1.715.5(3)s1.815.5(3)s1.915.5(3)s1.10
  • CVE-2018-0159Exploited list, 3 Mar 2022

    Cisco IOS and XE Software Internet Key Exchange Version 1 Denial-of-Service Vulnerability

    15.3(3)s
  • CVE-2018-0167Exploited list, 3 Mar 2022

    Cisco IOS, XR, and XE Software Buffer Overflow Vulnerability

    up to 15.6.3m1up to 15.2(6)e0aup to 15.2(4a)ea5
  • CVE-2018-0173Exploited list, 3 Mar 2022

    Cisco IOS and IOS XE Software Improper Input Validation Vulnerability

    up to 15.2(6)e0aup to 15.2(4a)ea5
  • CVE-2018-0174Exploited list, 3 Mar 2022

    Cisco IOS Software and Cisco IOS XE Software Improper Input Validation Vulnerability

    up to 15.2(4a)ea5up to 15.2(6)e0a
  • CVE-2018-0175Exploited list, 3 Mar 2022

    Cisco IOS, XR, and XE Software Buffer Overflow Vulnerability

    up to 15.2(4a)ea5up to 15.2(6)e0aup to 15.6.3m1
  • CVE-2017-6736Exploited list, 3 Mar 2022

    Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability

    2.2.0 to 3.17
  • CVE-2017-6663Exploited list, 3 Mar 2022

    Cisco IOS Software and Cisco IOS XE Software Denial-of-Service Vulnerability

    3.7.0e3.7.1e3.7.3e3.8.0e3.8.0ex3.8.1e3.8.2e3.8.3e
  • CVE-2017-6627Exploited list, 3 Mar 2022

    Cisco IOS Software and Cisco IOS XE Software UDP Packet Processing Denial-of-Service Vulnerability

    3.14.0s3.14.1s3.14.2s3.14.3s3.14.4s3.15.0s3.15.1cs3.15.1s
  • CVE-2017-12319Exploited list, 3 Mar 2022

    Cisco IOS XE Software Ethernet Virtual Private Network Border Gateway Protocol Denial-of-Service Vulnerability

    before 16.3
  • CVE-2017-6737Exploited list, 3 Mar 2022

    Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability

    2.2.0 to 3.17.0
  • CVE-2017-12237Exploited list, 3 Mar 2022

    Cisco IOS and IOS XE Software Internet Key Exchange Denial-of-Service Vulnerability

    3.5.0e to 16.5
  • CVE-2017-6738Exploited list, 3 Mar 2022

    Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability

    2.2.0 to 3.17.0

1 more exploited flaw names IOS XE without a version of its own, for example as the system other affected software runs on. It is in the list below.

Known exploited

Which IOS XE vulnerabilities are being exploited?

29 flaws are on the government list of vulnerabilities known to be exploited. These are the ones criminals are using now, so they go first, whatever their severity score says.

  1. 7.7
    CVE-2025-20352HighKnown exploited
    Cisco IOS and IOS XE Software SNMP Denial of Service and Remote Code Execution Vulnerability

    Cisco IOS and IOS XE contains a stack-based buffer overflow vulnerability in the Simple Network Management Protocol (SNMP) subsystem that could allow for denial of service or remote code execution.

    Chance of use42%Known exploited since29 Sep 2025
  2. 7.2
    CVE-2023-20273HighKnown exploited
    Cisco IOS XE Web UI Command Injection Vulnerability

    Cisco IOS XE contains a command injection vulnerability in the web user interface.

    Chance of use93%Known exploited since23 Oct 2023
  3. 7.2
    CVE-2021-1435HighKnown exploited
    Cisco IOS XE Web UI Command Injection Vulnerability

    Cisco IOS XE contains a command injection vulnerability in the web user interface that could allow a remote, authenticated attacker to inject commands that can be executed as the root user.

    Chance of use8.5%Known exploited since19 Oct 2023
  4. 10.0
    CVE-2023-20198CriticalKnown exploited
    Cisco IOS XE Web UI Privilege Escalation Vulnerability

    Cisco IOS XE Web UI contains a privilege escalation vulnerability in the web user interface that could allow a remote, unauthenticated attacker to create an account with privilege level 15 access.

    Chance of use>99%Known exploited since16 Oct 2023
  5. 7.5
    CVE-2023-44487HighKnown exploited
    HTTP/2 Rapid Reset Attack Vulnerability

    HTTP/2 contains a rapid reset vulnerability that allows for a distributed denial-of-service attack (DDoS).

    Chance of use>99%Known exploited since10 Oct 2023
  6. 6.6
    CVE-2023-20109MediumKnown exploited
    Cisco IOS and IOS XE Group Encrypted Transport VPN Out-of-Bounds Write Vulnerability

    Cisco IOS and IOS XE contain an out-of-bounds write vulnerability in the Group Encrypted Transport VPN (GET VPN) feature that could allow an authenticated, remote attacker who has administrative control of either a...

    Chance of use2.5%Known exploited since10 Oct 2023
  7. 7.5
    CVE-2016-6415HighKnown exploited
    Cisco IOS, IOS XR, and IOS XE IKEv1 Information Disclosure Vulnerability

    Cisco IOS, IOS XR, and IOS XE contain insufficient condition checks in the part of the code that handles Internet Key Exchange version 1 (IKEv1) security negotiation requests.

    Chance of use88%Known exploited since19 May 2023
  8. 8.8
    CVE-2017-6742HighKnown exploited
    Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability

    The Simple Network Management Protocol (SNMP) subsystem of Cisco IOS and IOS XE contains a vulnerability that could allow an authenticated, remote attacker to remotely execute code on an affected system or cause an...

    Chance of use21%Known exploited since19 Apr 2023
Exploit likelihood

Which IOS XE flaws are most likely to be used?

Ranked by the latest exploit-likelihood forecast: the chance each flaw is used in an attack in the next 30 days. A high severity score on its own doesn't tell you that. Flaws shared by many other makers' products are left out.

50% or more10% to 49%Under 10%
  1. >99%
    CVE-2023-44487HighKnown exploited

    The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.

    CVSS7.5Published10 Oct 2023
  2. 99%
    CVE-2017-3881CriticalKnown exploited

    A vulnerability in the Cisco Cluster Management Protocol (CMP) processing code in Cisco IOS and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a reload of an affected device or...

    CVSS9.8Published17 Mar 2017
  3. 93%
    CVE-2023-20273HighKnown exploited

    A vulnerability in the web UI feature of Cisco IOS XE Software could allow an authenticated, remote attacker to inject commands with the privileges of root.

    CVSS7.2Published25 Oct 2023
  4. 88%
    CVE-2016-6415HighKnown exploited

    The server IKEv1 implementation in Cisco IOS 12.2 through 12.4 and 15.0 through 15.6, IOS XE through 3.18S, IOS XR 4.3.x and 5.0.x through 5.2.x, and PIX before 7.0 allows remote attackers to obtain sensitive...

    CVSS7.5Published19 Sep 2016
  5. 70%
    CVE-2017-6736HighKnown exploited

    The Simple Network Management Protocol (SNMP) subsystem of Cisco IOS and IOS XE Software contains multiple vulnerabilities that could allow an authenticated, remote attacker to remotely execute code on an affected...

    CVSS8.8Published17 Jul 2017
  6. 45%
    CVE-2017-6737HighKnown exploited

    A vulnerability in the SNMP implementation of could allow an authenticated, remote attacker to cause a reload of the affected system or to remotely execute code.

    CVSS8.8Published17 Jul 2017
  7. 42%
    CVE-2025-20352HighKnown exploited

    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...

    CVSS7.7Published24 Sep 2025
  8. 35%
    CVE-2021-1384High

    A vulnerability in Cisco IOx application hosting environment of Cisco IOS XE Software could allow an authenticated, remote attacker to inject commands into the underlying operating system as the root user.

    CVSS7.2Published24 Mar 2021
  9. 29%
    CVE-2019-12650High

    Multiple vulnerabilities in the web-based user interface (Web UI) of Cisco IOS XE Software could allow an authenticated, remote attacker to execute commands with elevated privileges on the affected device.

    CVSS8.8Published25 Sep 2019
Precursor Intelligence

Running IOS XE? We'll keep checking.

Looking flaws up one at a time doesn't scale. Tell us what you run once, and we tell you which flaws matter to you, in what order, and keep watching for new ones.

  1. Tell us what you runPick your software from a list, or let us work it out from your website.
  2. We match it to every flawOver 400,000 published flaws, checked against your list.
  3. Ranked by real-world riskA 0 to 100 score, led by evidence criminals are using it.
  4. Told as soon as we knowAn alert by email, in the app or by webhook to your own tools.
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We track 506 published vulnerabilities listed under the name IOS XE, across 1,101 versions. The most recent IOS XE flaw added to the known-exploited list is CVE-2025-20352, on 29 September 2025.

29 are on the list of flaws known to be exploited. The most recently added are CVE-2025-20352, CVE-2023-20273 and CVE-2021-1435.

Cisco also lists IOS XE under more specific names, such as Ios XE SD-WAN and Ios XE 3.4sg. Flaws listed only under those names are counted on their own pages, not here. Open the release you run to see its own list.

Each flaw names its own versions, usually as ranges. The newest, CVE-2025-20352, affects 3.5.0e, 3.5.0sq, 3.5.1e, 3.5.1sq and more. The versions for every exploited flaw are listed on this page.

Create a Precursor Intelligence account and track IOS XE. We match it against every published flaw, give each one a risk score from 0 to 100 and keep watching, so you hear about new ones as soon as we know, by email, in the app or by webhook.

Keep exploring