CVE-2022-20856: Cisco IOS XE Wireless Controller Software for the Catalyst 9000 Family CAPWAP Mobility Denial of Service Vulnerability
Telemetry drift only. No threshold crossed and no authority ruling changed.
CVE record, CISA KEV and EPSS as of 2026-10-18.
CVEs like this one computed, by meaning
What to do now held facts and links
- No fix version is held. The CNA's first reference is the place to look: tools.cisco.com
- Record your decision, dated and frozen with today's evidence: patch by a date · mitigated by a compensating control · deferred · accepted the risk · not affected
- Check your version against the ranges this record publishes.
What it is stated by the CNA
A vulnerability in the processing of Control and Provisioning of Wireless Access Points (CAPWAP) Mobility messages in Cisco IOS XE Wireless Controller Software for the Catalyst 9000 Family could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to a logic error and improper management of resources related to the handling of CAPWAP Mobility messages. An attacker could exploit this vulnerability by sending crafted CAPWAP Mobility packets to an affected device. A successful exploit could allow the attacker to exhaust resources on the affected device. This would cause the device to reload, resulting in a DoS condition.
- weakness
- CWE-664
- affected
- Cisco IOS XE Software
- published ranges
- cisco ios xe 17.3.4c
- fixed in
- No fix version in held sources.
- severity
- 8.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- assigned by
- cisco
- published
- 2022-09-30
check us tools.cisco.com
Exploit code held, dated
- exploit code
- None held in the PoC-in-GitHub feed. A public repository changes this brief.
What moved held, dated
| date | EPSS | event |
|---|---|---|
| 1 Oct 2022 | 0.01055 | |
| 7 Mar 2023 | 0.00063 | scoring model v2023.03.01 |
| 8 Mar 2023 | 0.00063 | |
| 31 Aug 2023 | 0.00075 | |
| 17 Mar 2025 | 0.003 | scoring model v2025.03.14 |
| 15 Jun 2026 | 0.01083 | scoring model v2026.06.15 |
| 31 Jul 2026 | 0.01154 | |
| 5 Sep 2026 | 0.01177 | |
| 28 Sep 2026 | 0.01279 | |
| 17 Oct 2026 | 0.01288 |
27 observations held. A step marked with a scoring model moved because the measurement was replaced, not because the vulnerability changed.
Outside the record researched, cited
This section reads the record's references and adds cited findings from outside it. It needs an account. Everything above is held facts and is complete without it.
What would change this brief held, dated
- CISA KEV
- Not listed in the catalogue we hold. A listing changes this brief.
- exploit probability
- 0.01 on 2026-10-17 (FIRST's EPSS, a probability and not evidence of exploitation). Next band line: 10% (0.10). Crossing a line changes this brief.
- fix
- No fix version is held. One published by the CNA or OSV changes this brief.
How to check this
Every value above is held with two dates: when it was true upstream (as_of) and when we recorded it (tx_from). Re-derive the exploit probability as it stood on any date:
SELECT value, source, source_version, as_of, tx_from
FROM volatile_valid_as_of('CVE-2022-20856', '2026-10-31T23:59:59.999999Z', now());