CVE-2020-26896

Severity: high (CVSS 8.2 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-10-21 · updated 2026-06-17
Weakness: CWE-354

Description

Prior to 0.11.0-beta, LND (Lightning Network Daemon) had a vulnerability in its invoice database. While claiming on-chain a received HTLC output, it didn't verify that the corresponding outgoing off-chain HTLC was already settled before releasing the preimage. In the case of a hash-and-amount collision with an invoice, the preimage for an expected payment was instead released. A malicious peer could have deliberately intercepted an HTLC intended for the victim node, probed the preimage through a colluding relayed HTLC, and stolen the intercepted HTLC. The impact is a loss of funds in certain situations, and a weakening of the victim's receiver privacy.

Affected products

Lightning Network Daemon Project Lightning Network Daemon: before 0.11.0; 0.11.0, 0.11.0-beta_rc1, 0.11.0-beta_rc2, 0.11.0-beta_rc3, 0.11.0-beta_rc4 — fixed in 0.11.0

How to fix

Upgrade to a fixed version: Lightning Network Daemon Project Lightning Network Daemon 0.11.0. Check the vendor advisory for mitigations.

References

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