CVE-2026-20125A vulnerability in the HTTP Server feature of Cisco IOS Software and Cisco IOS XE Software Release 3E could allow an authenticated, remote…

Description

A vulnerability in the HTTP Server feature of Cisco IOS Software and Cisco IOS XE Software Release 3E could allow an authenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to improper validation of user-supplied input. An attacker could exploit this vulnerability by sending malformed HTTP requests to an affected device. A successful exploit could allow the attacker to cause a watchdog timer to expire and the device to reload, resulting in a DoS condition. To exploit this vulnerability, the attacker must have a valid user account.

Timeline

Scores

EPSS (exploitation in 30 days)

0.30% · top 77% of all CVEs (14 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.7.

Affected products

• Cisco · IOS

  • affected 12.2(33)CY
  • affected 12.2(33)CY1
  • affected 12.2(33)CY2
  • affected 12.2(55)SE
  • affected 12.2(55)SE3
  • affected 12.2(55)SE2
  • affected 12.2(58)SE
  • affected 12.2(55)SE1
  • affected 12.2(58)SE1
  • affected 12.2(55)SE4
  • affected 12.2(58)SE2
  • affected 12.2(55)SE5
  • affected 12.2(55)SE6
  • affected 12.2(55)SE7
  • affected 12.2(55)SE8
  • affected 12.2(55)SE9
  • affected 12.2(55)SE10
  • affected 12.2(55)SE11
  • affected 12.2(55)SE12
  • affected 12.2(55)SE13
  • affected 12.2(25)EZ
  • affected 12.2(25)EZ1
  • affected 12.2(58)EZ
  • affected 12.2(53)EZ
  • affected 12.2(55)EZ
  • affected 12.2(60)EZ
  • affected 12.2(60)EZ1
  • affected 12.2(60)EZ2
  • affected 12.2(60)EZ3
  • affected 12.2(60)EZ4
  • affected 12.2(60)EZ5
  • affected 12.2(60)EZ6
  • affected 12.2(60)EZ7
  • affected 12.2(60)EZ8
  • affected 12.2(60)EZ9
  • affected 12.2(60)EZ10
  • affected 12.2(60)EZ11
  • affected 12.2(60)EZ12
  • affected 12.2(60)EZ13
  • affected 12.2(60)EZ14
  • and 903 more

• Cisco · Cisco IOS XE Software

  • affected 3.5.0E
  • affected 3.5.1E
  • affected 3.5.2E
  • affected 3.5.3E
  • affected 3.11.1S
  • affected 3.11.2S
  • affected 3.11.0S
  • affected 3.11.3S
  • affected 3.11.4S
  • affected 3.12.0S
  • affected 3.12.1S
  • affected 3.12.2S
  • affected 3.12.3S
  • affected 3.12.0aS
  • affected 3.12.4S
  • affected 3.13.0S
  • affected 3.13.1S
  • affected 3.13.2S
  • affected 3.13.3S
  • affected 3.13.4S
  • affected 3.13.5S
  • affected 3.13.2aS
  • affected 3.13.0aS
  • affected 3.13.5aS
  • affected 3.13.6S
  • affected 3.13.7S
  • affected 3.13.6aS
  • affected 3.13.7aS
  • affected 3.13.8S
  • affected 3.13.9S
  • affected 3.13.10S
  • affected 3.6.0E
  • affected 3.6.1E
  • affected 3.6.2aE
  • affected 3.6.2E
  • affected 3.6.3E
  • affected 3.6.4E
  • affected 3.6.5E
  • affected 3.6.6E
  • affected 3.6.5aE
  • and 117 more

What to do

Exploitation: The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2026-15449 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-20125](https://cveledger.app/badge/CVE-2026-20125.svg)](https://cveledger.app/cve/CVE-2026-20125)

Record last updated 25 Mar 2026, 17:52 UTC.