No exploitation reported

CVE-2018-1000836

Q: Is CVE-2018-1000836 actively exploited?

Active exploitation of CVE-2018-1000836 has not been confirmed. Its EPSS score was 1.1% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2018-1000836?

CVE-2018-1000836 has a CVSS v3 base score of 9 (CRITICAL severity), with vector string CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2018-12-20
WeaknessCWE-611

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

bw-calendar-engine version <= bw-calendar-engine-3.12.0 contains a XML External Entity (XXE) vulnerability in IscheduleClient XML Parser that can result in Disclosure of confidential data, denial of service, SSRF, port scanning. This attack appear to be exploitable via Man in the Middle or malicious server.

Timeline

dates in UTC

2018-12-2015:29CVE 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-2018-1000836?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2018-1000836?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV

Apereo bw-calendar-engine

Branch	Affected	Fixed in	Source
3.12	≤ 3.12.0	no fix published	NVD

bw-calendar-engine

Branch	Affected	Fixed in	Source
3.12	≤ 3.12.2	no fix published	OSV

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

Fix

No fix published by the sources we read yet. NVD record

Detection

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

Sources

NVDCVSS 3.09read 2026-10-23
NVDCVSS 2.06.8read 2026-10-23
NVDweakness (CWE)CWE-611read 2026-10-23
FIRST EPSSEPSS score1.1 %2026-10-22
OSVaffected packages—

Technical details

CVSS v3 Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Published: 2018-12-20
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2018-1000836?

Is CVE-2018-1000836 actively exploited?

Active exploitation of CVE-2018-1000836 has not been confirmed. Its EPSS score was 1.1% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2018-1000836?

CVE-2018-1000836 has a CVSS v3 base score of 9 (CRITICAL severity), with vector string CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H.

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