CVE-2026-123556 json
Zebra 4.5.0 before 7.0.0 Honest Peer Ban via Mempool Lock-Time Scoring
published 20d ago modified 4d ago also EUVD-2026-119441 , GHSA-5h3r-fpmj-483w
Unreviewed: the maintainers' own advisory
Published by the maintainers on their GitHub repository ZcashFoundation/zebra. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.
- cvss
- 5.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 23%
- public exploits
- 0
- none known
Summary
ZcashFoundation Zebra from 4.5.0 before 7.0.0 contains a protection mechanism failure that bans honest peers by scoring mempool lock-time rejections at the ban threshold. Attackers can broadcast transactions locked until the current height right after each block, causing lagging nodes to ban honest relaying peers for 24 hours or until restart.
Patch / fix
- ZcashFoundation zebra 7.0.0
Is CVE-2026-123556 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerExploit prediction
0.30% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-11).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 6.9 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N |
| CNA | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
| CNA | 4.0 | 6.9 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| NVD | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
Affected products
- ZcashFoundation zebra
Classification
- Weakness
-
- CWE-693 Protection Mechanism Failure
References
-
github.com
/ZcashFoundation/zebra/security/advisories/GHSA-5h3r-fpmj-483w
vendor-advisory, advisory
-
vulncheck.com
/advisories/zebra-4.5.0-before-7.0.0-honest-peer-ban-via-mempool-lock-time-scoring
third-party-advisory
Sources
- CVE List CVE-2026-123556
- NVD CVE-2026-123556
- Maintainer advisory GHSA-5h3r-fpmj-483w
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
The maintainers of ZcashFoundation/zebra published their own advisory on GitHub. Reviewed sources take precedence over it.