CVE-2020-26896

CVE-2020-26896 is a high-severity vulnerability in Lightning Network Daemon Project Lightning Network Daemon with a CVSS 3.x base score of 8.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-354.

Key facts

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.

Frequently asked questions

What is CVE-2020-26896?
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.
How severe is CVE-2020-26896?
CVE-2020-26896 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability none.
Is CVE-2020-26896 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-26896?
CVE-2020-26896 primarily affects Lightning Network Daemon Project Lightning Network Daemon. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-26896?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-26896 published?
CVE-2020-26896 was published on 2020-10-21 and last updated on 2026-06-17.

References

Affected products (6)

More vulnerabilities in Lightning Network Daemon Project Lightning Network Daemon

All CVEs affecting Lightning Network Daemon Project Lightning Network Daemon →

Other CWE-354 vulnerabilities

Browse all CWE-354 vulnerabilities →