CVE-2018-0158: Cisco IOS and XE Software Internet Key Exchange Memory Leak Vulnerability
Actively exploited. At least one CVE in this advisory is listed in the CISA Known Exploited Vulnerabilities catalog — exploitation has been observed in the wild. Treat remediation as urgent.
A vulnerability in the implementation of Internet Key Exchange Version 1 (IKEv1) functionality in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial-of-service (DoS) condition.
CSIRTS triage
- What
- A vulnerability in the implementation of Internet Key Exchange Version 1 (IKEv1) functionality could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial-of-service (DoS) condition.
- Who is affected
- Users of Cisco IOS and XE Software are affected by this vulnerability.
- Urgency
- Remediation is critical due to the potential for denial of service and confirmed exploitation.
- Action
- Update to the latest version of Cisco IOS and XE Software.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2018-0158
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Exploitation confirmedCVE-2018-0158Already exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 94% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2018-0158 | coverage & exploitation status | NVD · CVE.org |
Recent advisories for Cisco IOS and
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
- unknownMultiple vulnerabilities in Cisco IOS XE (August 25, 2026)cert-fr-avis · 2026-08-25
- unknownNCSC-2026-0279 [1.00] [M/H] Vulnerabilities patched in Cisco IOS XE Softwarencsc-nl · 2026-08-07
- high[NEW] [high] Cisco IOS: Vulnerability Enables Denial of Servicecert-bund · 2026-08-06
- high[NEW] [high] Cisco IOS XE: Multiple Vulnerabilitiescert-bund · 2026-08-06
- mediumCVE-2026-20311: A vulnerability in the web-based management interface of Cisco IOS XE Software could allow an …nvd · 2026-08-05
- mediumCVE-2026-20308: A vulnerability in the web-based management interface of Cisco IOS XE Software could allow an …nvd · 2026-08-05
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