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Fencer Intel
high 7.4

CVE-2026-104437 json

Zebra before 4.4.0 Consensus Split via SIGHASH_SINGLE Missing-Output Handling

published 6mo ago modified last mo. also EUVD-2026-91447 , GHSA-cwfq-rfcr-8hmp

cvss
7.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 16%
public exploits
0
none known

Summary

Zebra before 4.4.0 contains a consensus divergence vulnerability in V5 transparent signature verification, computing a ZIP-244 digest for SIGHASH_SINGLE inputs lacking corresponding outputs instead of failing. Attackers can craft V5 transactions with fewer outputs than inputs that Zebra accepts and templates via getblocktemplate, producing blocks zcashd rejects.

Patch / fix

  • crates.io zebrad 4.4.0
  • ZcashFoundation zebra 4.4.0

Is CVE-2026-104437 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
last mo.

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 16% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-cwfq-rfcr-8hmp referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 8.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N
CNA 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H
CNA 4.0 8.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/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 packages

ecosystem package affected fixed in
crates.io zebrad
<4.4.0
4.4.0

Affected products

  • ZcashFoundation zebra

Classification

Weakness
  • CWE-347 Improper Verification of Cryptographic Signature
  • CWE-354 Improper Validation of Integrity Check Value
  • CWE-573 Improper Following of Specification by Caller

References

Sources

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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.