No exploitation reportedFix available

CVE-2020-27718

Q: Is CVE-2020-27718 actively exploited?

Active exploitation of CVE-2020-27718 has not been confirmed. Its EPSS score was 1.0% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2020-27718?

CVE-2020-27718 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

No exploitation reported by the sources we read.

Published2020-12-24
Fixed in16.0.1 · 15.1.1 · 14.1.3.1 · 13.1.3.5

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

When a BIG-IP ASM or Advanced WAF system running version 16.0.0-16.0.0.1, 15.1.0-15.1.0.5, 14.1.0-14.1.3, 13.1.0-13.1.3.4, 12.1.0-12.1.5.2, or 11.6.1-11.6.5.2 processes requests with JSON payload, an unusually large number of parameters can cause excessive CPU usage in the BIG-IP ASM bd process.

Timeline

dates in UTC

2020-12-2415:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-27718?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-27718?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

F5 big-ip advanced web application firewall

Branch	Affected	Fixed in	Source
16.0	≥ 16.0.0, < 16.0.1	16.0.1	NVD
15.x	≥ 15.0.0, < 15.1.1	15.1.1	NVD
14.1	≥ 14.1.0, < 14.1.3.1	14.1.3.1	NVD
13.1	≥ 13.1.0, < 13.1.3.5	13.1.3.5	NVD
11.6	≥ 11.6.1, ≤ 11.6.5	no fix published	NVD
12.1	≥ 12.1.0, ≤ 12.1.5	no fix published	NVD

F5 big-ip application security manager

Branch	Affected	Fixed in	Source
16.0	≥ 16.0.0, < 16.0.1	16.0.1	NVD
15.x	≥ 15.0.0, < 15.1.1	15.1.1	NVD
14.1	≥ 14.1.0, < 14.1.3.1	14.1.3.1	NVD
13.1	≥ 13.1.0, < 13.1.3.5	13.1.3.5	NVD
11.6	≥ 11.6.1, ≤ 11.6.5	no fix published	NVD
12.1	≥ 12.1.0, ≤ 12.1.5	no fix published	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update F5 big-ip advanced web application firewall to 16.0.1 · 15.1.1 · 14.1.3.1 · 13.1.3.5

Advisories and patches

support.f5.comVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.17.5read 2026-10-23
NVDCVSS 2.05read 2026-10-23
FIRST EPSSEPSS score1.0 %2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: 2020-12-24
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2020-27718?

Is CVE-2020-27718 actively exploited?

Active exploitation of CVE-2020-27718 has not been confirmed. Its EPSS score was 1.0% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-27718?

CVE-2020-27718 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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