No exploitation reportedFix available

CVE-2021-43839

Q: Is CVE-2021-43839 actively exploited?

Active exploitation of CVE-2021-43839 has not been confirmed. Its EPSS score was 1.4% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2021-43839?

CVE-2021-43839 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:H/A:N.

No exploitation reported by the sources we read.

Published2021-12-21
Fixed in0.10.0 · 0.7.3
WeaknessCWE-670

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

Cronos is a commercial implementation of a blockchain. In Cronos nodes running versions before v0.6.5, it is possible to take transaction fees from Cosmos SDK's FeeCollector for the current block by sending a custom crafted MsgEthereumTx. This problem has been patched in Cronos v0.6.5. There are no tested workarounds. All validator node operators are recommended to upgrade to Cronos v0.6.5 at their earliest possible convenience.

Timeline

dates in UTC

2021-12-2117:15CVE 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-2021-43839?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-43839?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

OSV · NVD

Crypto ethermint

Branch	Affected	Fixed in	Source
0.x	≥ 0.8.0, < 0.10.0	0.10.0	OSV
0.7	< 0.7.3	0.7.3	NVD · OSV
0.x	≥ 0.8.0, ≤ 0.9.0	no fix published	NVD

Crypto cronos

Branch	Affected	Fixed in	Source
0.6	< 0.6.5	0.6.5	NVD · OSV

Crypto evmos

Branch	Affected	Fixed in	Source
0.4	≤ 0.4.2	no fix published	NVD

1 more product in the sources.

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

Fix

Update Crypto ethermint to 0.10.0 · 0.7.3

Advisories and patches

github.comPatch
github.comPatch

Detection

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

Sources

CNACVSS 3.17.5read 2026-10-23
NVDCVSS 2.05read 2026-10-23
CNAweakness (CWE)CWE-670read 2026-10-23
NVDweakness (CWE)CWE-670read 2026-10-23
FIRST EPSSEPSS score1.4 %2026-10-23
OSVaffected packages—

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Published: 2021-12-21
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2021-43839?

Is CVE-2021-43839 actively exploited?

Active exploitation of CVE-2021-43839 has not been confirmed. Its EPSS score was 1.4% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-43839?

CVE-2021-43839 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:H/A:N.

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