# CVE-2020-26895: Business logic in n/a

> Attackers can exploit signature validation flaws to broadcast invalid transactions, resulting in potential loss of funds for LND users.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 21 Oct 2020
- **Updated:** 4 Aug 2024

## What is CVE-2020-26895?

CVE-2020-26895 is a medium-severity vulnerability in n/a, published on 21 Oct 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Prior to 0.10.0-beta, LND (Lightning Network Daemon) would have accepted a counterparty high-S signature and broadcast tx-relay invalid local commitment/HTLC transactions. This can be exploited by any peer with an open channel regardless of the victim situation (e.g., routing node, payment-receiver, or payment-sender). The impact is a loss of funds in certain situations.

Weakness: CWE-354 (Improper Validation of Integrity Check Value)

## Which versions are affected by CVE-2020-26895?

It affects 1 product.


Products: Lightning Network Daemon Project Lightning Network Daemon.

## How do I fix CVE-2020-26895?

No fix has been published for CVE-2020-26895 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-26895 being exploited?

There is no known exploitation of CVE-2020-26895 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2021-41593](https://insights.sbomify.com/CVE-2021-41593/): Business logic in n/a (high 8.6)
- [CVE-2020-26896](https://insights.sbomify.com/CVE-2020-26896/): Business logic in n/a (high 8.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-26895 and fix it if it is affected.

What it is: CVE-2020-26895 is a medium-severity vulnerability in n/a, published on 21 Oct 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-26895 in the wild and no public exploit code.

Affected product: n/a. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2020-26895/ (Markdown: https://insights.sbomify.com/CVE-2020-26895/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-26895
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-26895
- OSV: https://osv.dev/vulnerability/CVE-2020-26895

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-26895/
Summaries are generated and may contain mistakes; the official description above is the record.