CVE-2021-41591

Name: CVE-2021-41591
Creator: NVD / NIST
Published: 2021-10-04T17:15:08.627+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.4/10EPSS 1.65%

Last modified Jun 17, 2026

CVE-2021-41591 is a critical-severity vulnerability rated 9.4/10 on the CVSS scale. ACINQ Eclair before 0.6.3 allows loss of funds because of dust HTLC exposure.. EPSS estimates a 1.65% chance of exploitation in the next 30 days.

Description

ACINQ Eclair before 0.6.3 allows loss of funds because of dust HTLC exposure.

Metrics

CVSS 3.1

9.4/10

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

EPSS Probability

1.65%

73.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-770

Affected Software

Vendor	Product	Versions
Acinq	Eclair	< 0.6.3

References

https://bitcoinmagazine.com/technical/good-griefing-a-lingering-vulnerability-on-lightning-network-that-still-needs-fixingPress/Media Coverage
https://github.com/ACINQ/eclair/pull/1985Patch, Third Party Advisory
https://lists.linuxfoundation.org/pipermail/lightning-dev/2020-May/002714.htmlMailing List, Vendor Advisory
https://lists.linuxfoundation.org/pipermail/lightning-dev/2021-October/003257.htmlExploit, Vendor Advisory
https://bitcoinmagazine.com/technical/good-griefing-a-lingering-vulnerability-on-lightning-network-that-still-needs-fixingPress/Media Coverage
https://github.com/ACINQ/eclair/pull/1985Patch, Third Party Advisory
https://lists.linuxfoundation.org/pipermail/lightning-dev/2020-May/002714.htmlMailing List, Vendor Advisory
https://lists.linuxfoundation.org/pipermail/lightning-dev/2021-October/003257.htmlExploit, Vendor Advisory

Timeline

Published: Oct 4, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-41591?

ACINQ Eclair before 0.6.3 allows loss of funds because of dust HTLC exposure.

How severe is CVE-2021-41591?

CVE-2021-41591 has a CVSS score of 9.4/10 (CRITICAL severity). The EPSS model estimates a 1.65% probability of exploitation in the next 30 days.

How do I fix CVE-2021-41591?

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-2021-41591?

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

Scan your code now

Source: NVD / NIST