How severe is CVE-2018-5545?

CVE-2018-5545 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2018-5545 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-5545?

CVE-2018-5545 affects F5 Websafe Alert Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-5545?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2018-5545 published?

CVE-2018-5545 was published on 2018-09-13 and last updated on 2026-06-17.

CVE-2018-5545

CVE-2018-5545 is a high-severity vulnerability in F5 Websafe Alert Server with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.5
EPSS exploit prediction: 2% (82nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: F5 Websafe Alert Server
Published: 2018-09-13
Last modified: 2026-06-17

Description

On F5 WebSafe Alert Server 1.0.0-4.2.6, a malicious, authenticated user can execute code on the alert server by using a maliciously crafted payload.

Frequently asked questions

What is CVE-2018-5545?: On F5 WebSafe Alert Server 1.0.0-4.2.6, a malicious, authenticated user can execute code on the alert server by using a maliciously crafted payload.
How severe is CVE-2018-5545?: CVE-2018-5545 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-5545 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-5545?: CVE-2018-5545 affects F5 Websafe Alert Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-5545?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2018-5545 published?: CVE-2018-5545 was published on 2018-09-13 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:f5:websafe_alert_server:*:*:*:*:*:*:*:*

More vulnerabilities in F5 Websafe Alert Server

CVE-2016-5235 — Medium (CVSS 6.1): A Cross Site Scripting (XSS) vulnerability in versions of F5 WebSafe Dashboard 3.9.x and earlier, aka F5 WebSafe Alert…
CVE-2016-5236 — Medium (CVSS 5.4): Cross-Site-Scripting (XSS) vulnerabilities in F5 WebSafe Dashboard 3.9.5 and earlier, aka F5 WebSafe Alert Server,…

All CVEs affecting F5 Websafe Alert Server →

Other CWE-20 (Improper Input Validation) vulnerabilities

CVE-2026-48316 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48281 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48277 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48055 — Critical (CVSS 10.0): Streambert is a cross-platform Electron Desktop App to stream and download any video media. In versions 2.4.0 and…
CVE-2026-34910 — Critical (CVSS 10.0): A malicious actor with access to the network could exploit an Improper Input Validation vulnerability found in UniFi OS…
CVE-2026-33587 — Critical (CVSS 10.0): Lack of user input sanitisation in Open Notebook v1.8.3 allows the application user to execute Python code (and…

Browse all CWE-20 (Improper Input Validation) vulnerabilities →