Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Zebrad versions up to and including 4.4.1 and zebra-chain versions before 8.0.0 accept block locator vectors of up to about 65,535 entries in getblocks and getheaders messages, far beyond the protocol limit of 101. A remote attacker with inbound P2P access can send oversized locators, which occupy blocking-pool threads with per-hash chain lookups and can degrade state reads under sustained multi-peer load. Upgrade zebrad to 4.5.0 and zebra-chain to 8.0.0. The source lists no workaround beyond existing backpressure.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 6.3 | Medium | 4.0 | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N | CNA (VulnCheck) |
- CISA KEV Not listed.
- EPSS 0.0027, the 19th percentile, on 15 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:24 UTC First seen by agentprime
- 31 Oct 2026, 14:24 UTC Confirmed by OSV