No exploitation reportedFix available

CVE-2020-11637

Q: Is CVE-2020-11637 actively exploited?

Active exploitation of CVE-2020-11637 has not been confirmed. Its EPSS score was 1.1% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2020-11637?

CVE-2020-11637 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.

Published2020-10-15
Fixed inn4.34 · n4.26 · f4.45 · e4.53 · d4.63 · a4.73
WeaknessCWE-401

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

A memory leak in the TFTP service in B&R Automation Runtime versions <N4.26, <N4.34, <F4.45, <E4.53, <D4.63, <A4.73 and prior could allow an unauthenticated attacker with network access to cause a denial of service (DoS) condition.

Timeline

dates in UTC

2020-10-1516:15CVE 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-2020-11637?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-11637?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Br-automation automation runtime

Branch	Affected	Fixed in	Source
4.30+	≥ 4.30, < n4.34	n4.34	NVD
4.20+	≥ 4.20, < n4.26	n4.26	NVD
4.40+	≥ 4.40, < f4.45	f4.45	NVD
4.50+	≥ 4.50, < e4.53	e4.53	NVD
4.60+	≥ 4.60, < d4.63	d4.63	NVD
4.70+	≥ 4.70, < a4.73	a4.73	NVD
4.10	≤ 4.10	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 Br-automation automation runtime to n4.34 · n4.26 · f4.45 · e4.53 · d4.63 · a4.73

Advisories and patches

www.br-automation.comVendor Advisory

Detection

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

Sources

CNACVSS 3.15.8read 2026-10-23
NVDCVSS 3.17.5read 2026-10-23
NVDCVSS 2.05read 2026-10-23
CNAweakness (CWE)CWE-401read 2026-10-23
NVDweakness (CWE)CWE-401read 2026-10-23
FIRST EPSSEPSS score1.1 %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: 2020-10-15
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2020-11637?

Is CVE-2020-11637 actively exploited?

Active exploitation of CVE-2020-11637 has not been confirmed. Its EPSS score was 1.1% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-11637?

CVE-2020-11637 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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