CVE-2026-123555 json
Zebra 2.3.0 before 7.0.0 Denial of Service via Unscored Script Verification Failures
published 20d ago modified 4d ago also EUVD-2026-119440 , GHSA-jq45-ghw5-v37x
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
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 37%
- public exploits
- 0
- none known
Summary
Zebra from 2.3.0 before 7.0.0 contains a denial of service vulnerability that allows unauthenticated peers to evade misbehavior scoring by sending transactions or blocks with invalid transparent scripts. Attackers can flood mempool with script-failing transactions or serve forged v5 block bodies with altered scriptSig bytes to exhaust CPU and repeatedly stall block sync.
Patch / fix
Is CVE-2026-123555 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
0.43% chance of exploitation in the next 30 days, higher than 37% of all scored CVEs (FIRST EPSS, 2026-11-11).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 8.7 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N |
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| CNA | 4.0 | 8.7 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Affected products
- ZcashFoundation zebra
Classification
- Weakness
-
- CWE-755 Improper Handling of Exceptional Conditions
References
-
github.com
/ZcashFoundation/zebra/commit/e8db87eb69254e0d4eedd058eadd48bdfa09065a
patch
-
github.com
/ZcashFoundation/zebra/security/advisories/GHSA-jq45-ghw5-v37x
vendor-advisory, advisory
-
vulncheck.com
/advisories/zebra-2.3.0-before-7.0.0-denial-of-service-via-unscored-script-verification-failures
third-party-advisory
Sources
- CVE List CVE-2026-123555
- NVD CVE-2026-123555
- Maintainer advisory GHSA-jq45-ghw5-v37x
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.