CVE-2026-123554 json
Zebra zebrad 6.4.0 before 7.0.0 Denial of Service via Mempool Coinbase-Maturity Check
published 20d ago modified 2d ago also EUVD-2026-119439 , GHSA-7jp4-mq53-4cvq
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 zebrad 6.4.0 before 7.0.0 performs quadratic work in the mempool coinbase-maturity check because Transaction::coinbase_spend_restriction() rebuilds the transaction's output list once per spent outpoint. Any connected peer can repeatedly send unsigned transactions with many transparent inputs and outputs, which are rejected without a misbehavior score, to pin verification threads.
Patch / fix
Is CVE-2026-123554 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 FencerCISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 2d ago
Exploit 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 |
Affected products
- ZcashFoundation zebra
Classification
- Weakness
-
- CWE-407 Inefficient Algorithmic Complexity
References
-
github.com
/ZcashFoundation/zebra/commit/08743d669b33a19bce2a5d54001bd468c03a196e
patch
-
github.com
/ZcashFoundation/zebra/security/advisories/GHSA-7jp4-mq53-4cvq
vendor-advisory, advisory
-
vulncheck.com
/advisories/zebra-zebrad-6.4.0-before-7.0.0-denial-of-service-via-mempool-coinbase-maturity-check
third-party-advisory
Sources
- CVE List CVE-2026-123554
- NVD CVE-2026-123554
- Maintainer advisory GHSA-7jp4-mq53-4cvq
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.