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 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.
EPSS 0.20% · 42.3th percentile
Risk Scores
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Cisco IOS XE Software | 3.5.0E, 3.5.1E, 3.5.2E |
| Cisco | IOS | 12.2(33)CY, 12.2(33)CY2, 12.2(55)SE |
Exploit Intelligence
- cisco-sa-iosxe-tls-dos-TVgLDEZL (circl)
- CIRCL seen: CVE-2026-20004 (circl-sighting)
- CIRCL seen: CVE-2026-20004 (circl-sighting)
- CIRCL seen: CVE-2026-20004 (circl-sighting)
- CIRCL seen: CVE-2026-20004 (circl-sighting)
- CIRCL seen: CVE-2026-20004 (circl-sighting)
- CIRCL seen: CVE-2026-20125 (circl-sighting)
- CIRCL seen: CVE-2026-20125 (circl-sighting)
- CIRCL seen: CVE-2026-20125 (circl-sighting)
- CIRCL seen: CVE-2026-20125 (circl-sighting)
…and 2 more exploits
Timeline
- Mar 25, 2026 Coalition ESS Score
- Mar 25, 2026 CVE Published
- Mar 25, 2026 CVE Updated
- Mar 25, 2026 PoC Published
- Mar 26, 2026 PoC Published
- Mar 26, 2026 PoC Published
- Mar 26, 2026 PoC Published
- Mar 26, 2026 PoC Published
- Mar 26, 2026 PoC Published
- Mar 26, 2026 PoC Published
- Mar 29, 2026 Security Advisory
- May 18, 2026 EPSS Score
References
- cisco-sa-ios-http-dos-sbv8XRpL url
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-ios-dos-kPEpQGGK advisory
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-xe-secureboot-bypass-B6uYxYSZ advisory
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-bootp-WuBhNBxA advisory
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-wlc-dos-hnX5KGOm advisory
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-tls-dos-TVgLDEZL advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-20125 advisory