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Fencer Vulns
medium 5.3

CVE-2026-44500 json

ZEBRA: Allocation Amplification in Inbound Network Deserializers

published 2026-05-07 6 mo ago modified 2026-10-26 13 d ago also GHSA-438q-jx8f-cccv , EUVD-2026-28784

cvss
5.3
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 30%
public exploits
0
none known

Summary

ZEBRA is a Zcash node written entirely in Rust. Prior to zebrad version 4.4.0, prior to zebra-chain version 7.0.0, and prior to zebra-network version 6.0.0, several inbound deserialization paths in Zebra allocated buffers sized against generic transport or block-size ceilings before the tighter protocol or consensus limits were enforced. An unauthenticated or post-handshake peer could therefore force the node to preallocate and parse for orders of magnitude more data than the protocol intended, across headers messages, equihash solutions in block headers, Sapling spend vectors in V5/V4 transactions, and coinbase script bytes in blocks. This issue has been patched in zebrad version 4.4.0, zebra-chain version 7.0.0, and zebra-network version 6.0.0.

Patch / fix

  • crates.io zebra-network 6.0.0
  • crates.io zebrad 4.4.0
  • crates.io zebra-chain 7.0.0
  • zfnd zebra-chain 7.0.0
  • zfnd zebra-network 6.0.0
  • zfnd zebrad 4.4.0

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
6 mo ago

Exploit prediction

0.36% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-438q-jx8f-cccv referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
GitHub 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected packages

ecosystem package affected fixed in
crates.io zebra-network
<6.0.0
6.0.0
crates.io zebrad
<4.4.0
4.4.0
crates.io zebra-chain
<7.0.0
7.0.0

Affected products

  • ZcashFoundation zebra

Classification

Weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling

References

Sources

Fencer Vulns 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.