No exploitation reportedFix available

CVE-2021-43834

Q: Is CVE-2021-43834 actively exploited?

Active exploitation of CVE-2021-43834 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-2021-43834?

CVE-2021-43834 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2021-12-16
Fixed in4.2.0
WeaknessCWE-287

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

eLabFTW is an electronic lab notebook manager for research teams. In versions prior to 4.2.0 there is a vulnerability which allows an attacker to authenticate as an existing user, if that user was created using a single sign-on authentication option such as LDAP or SAML. It impacts instances where LDAP or SAML is used for authentication instead of the (default) local password mechanism. Users should upgrade to at least version 4.2.0.

Timeline

dates in UTC

2021-12-1600:15CVE 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-2021-43834?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-43834?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Elabftw

Branch	Affected	Fixed in	Source
4.2	< 4.2.0	4.2.0	NVD

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

Fix

Update Elabftw to 4.2.0

Advisories and patches

github.comRelease Notes

Detection

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

Sources

CNACVSS 3.19.1read 2026-10-23
NVDCVSS 3.19.8read 2026-10-23
NVDCVSS 2.06.5read 2026-10-23
CNAweakness (CWE)CWE-287read 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:H/I:H/A:H
Published: 2021-12-16
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2021-43834?

Is CVE-2021-43834 actively exploited?

Active exploitation of CVE-2021-43834 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-2021-43834?

CVE-2021-43834 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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