Public proof of conceptFix available

CVE-2023-42820

Q: Is CVE-2023-42820 actively exploited?

Active exploitation of CVE-2023-42820 has not been confirmed. Its EPSS score was 6.3% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2023-42820?

CVE-2023-42820 has a CVSS v3 base score of 8.2 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N.

A public proof of concept exists; no exploitation attested.

Published2023-09-27
Fixed in3.6.5 · 2.28.19
WeaknessCWE-200

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

JumpServer is an open source bastion host. This vulnerability is due to exposing the random number seed to the API, potentially allowing the randomly generated verification codes to be replayed, which could lead to password resets. If MFA is enabled users are not affect. Users not using local authentication are also not affected. Users are advised to upgrade to either version 2.28.19 or to 3.6.5. There are no known workarounds or this issue.

Timeline

dates in UTC

2023-09-2715:19CVE publishedNVD
2026-10-2319:23First public proof of conceptPoC-in-GitHub

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-2023-42820?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2023-42820?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Fit2cloud jumpserver

Branch	Affected	Fixed in	Source
3.x	≥ 3.0.0, < 3.6.5	3.6.5	NVD
2.x	≥ 2.24.0, < 2.28.19	2.28.19	NVD

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

Fix

Update Fit2cloud jumpserver to 3.6.5 · 2.28.19

Advisories and patches

github.comPatch
github.comVendor Advisory

Detection

read 2026-10-23 19:23 UTC

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: 2 repositories, unverifiedC1ph3rX13/CVE-2023-42820Startr4ck/cve-2023-42820

Sources

CISA-ADPSSVC decisionnone2024-09-23
OpenCVESSVC decisionnone—
CNACVSS 3.17read 2026-10-23
NVDCVSS 3.18.2read 2026-10-23
CNAweakness (CWE)CWE-200read 2026-10-23
FIRST EPSSEPSS score6.3 %2026-10-22
PoC-in-GitHubproof of concept2read 2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
Published: 2023-09-27
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2023-42820?

Is CVE-2023-42820 actively exploited?

Active exploitation of CVE-2023-42820 has not been confirmed. Its EPSS score was 6.3% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2023-42820?

CVE-2023-42820 has a CVSS v3 base score of 8.2 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N.

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