PatchTheCVECVE-2024-55563: Bitcoin Core through 27.2 allows transaction-relay jamming via an off-chain protocol attack, a related issue t
CVE-2024-55563 is a medium-severity flaw (CVSS 5.3) affecting bitcoin core. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Bitcoin Core through 27.2 allows transaction-relay jamming via an off-chain protocol attack, a related issue to CVE-2024-52913. For example, the outcome of an HTLC (Hashed Timelock Contract) can be changed because a flood of transaction traffic prevents propagation of certain Lightning channel transactions.
Why this priority
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 5.3 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.7% (top 48%) |
| CISA exploited list | No |
| Weakness | CWE-770 |
| Published | 2024-12-09 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2024-55563?
bitcoin core: upgrade to newer than 27.2. Exact commands for each OS are on this page.
Is CVE-2024-55563 being exploited?
CVE-2024-55563 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2024-55563 affect?
CVE-2024-55563 affects bitcoin core. Severity is medium (CVSS 5.3). Bitcoin Core through 27.2 allows transaction-relay jamming via an off-chain protocol attack, a related issue to CVE-2024-52913. For example, the outcome of an HTLC (Hashed Timelock Contract) can be changed because a flood of transaction tra
How urgent is CVE-2024-55563?
Priority 37/100. Remotely exploitable, no login, no user action
Related CVEs
- CVE-2025-54605 HIGH 7.5 UPGRADE Bitcoin Core through 29.0 allows Uncontrolled Resource Consumption (issue 2 of 2).
- CVE-2025-54604 HIGH 7.5 UPGRADE Bitcoin Core through 29.0 allows Uncontrolled Resource Consumption (issue 1 of 2).
- CVE-2025-46598 MEDIUM 5.3 UPGRADE Bitcoin Core through 29.0 allows a denial of service via a crafted transaction.
- CVE-2025-46597 HIGH 7.5 UPGRADE Bitcoin Core 0.13.0 through 29.x has an integer overflow.
- CVE-2024-52922 MEDIUM 6.5 UPGRADE In Bitcoin Core before 25.1, an attacker can cause a node to not download the latest block, because there can