CVE-2020-15091

Name: CVE-2020-15091
Creator: NVD / NIST
Published: 2020-07-02T17:15:12.547+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 0.91%

Last modified Jun 17, 2026

CVE-2020-15091 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. TenderMint from version 0.33.0 and before version 0.33.6 allows block proposers to include signatures for the wrong block. This may happen naturally if you start a network, have it run for some time and restart it (**without changing chainID**). EPSS estimates a 0.91% chance of exploitation in the next 30 days.

Description

TenderMint from version 0.33.0 and before version 0.33.6 allows block proposers to include signatures for the wrong block. This may happen naturally if you start a network, have it run for some time and restart it (**without changing chainID**). A malicious block proposer (even with a minimal amount of stake) can use this vulnerability to completely halt the network. This issue is fixed in Tendermint 0.33.6 which checks all the signatures are for the block with 2/3+ majority before creating a commit.

Metrics

CVSS 3.1

6.5/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.91%

55.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Tendermint	Tendermint	>= 0.33.0, < 0.33.6

References

https://github.com/tendermint/tendermint/commit/480b995a31727593f58b361af979054d17d84340Patch, Third Party Advisory
https://github.com/tendermint/tendermint/issues/4926Exploit, Issue Tracking, Third Party Advisory
https://github.com/tendermint/tendermint/security/advisories/GHSA-6jqj-f58p-mrw3Exploit, Third Party Advisory
https://github.com/tendermint/tendermint/commit/480b995a31727593f58b361af979054d17d84340Patch, Third Party Advisory
https://github.com/tendermint/tendermint/issues/4926Exploit, Issue Tracking, Third Party Advisory
https://github.com/tendermint/tendermint/security/advisories/GHSA-6jqj-f58p-mrw3Exploit, Third Party Advisory

Timeline

Published: Jul 2, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-15091?

How severe is CVE-2020-15091?

CVE-2020-15091 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.91% probability of exploitation in the next 30 days.

How do I fix CVE-2020-15091?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-15091?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST