CVE-2026-44500 | ZEBRA: Allocation Amplification in Inbound Network Deserializers

Exp

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.

Published: 2026-05-08 Last update: 2026-05-08 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-44500 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-44500

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-44500

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-22 0.06% 0.02% -0.04%
2 2026-05-14 0.05% 0.06% +0.02%
3 2026-05-09 — 0.05% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-44500

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 1.4 [email protected]

Weakness enumeration for CVE-2026-44500

GitHub Security Advisory for CVE-2026-44500

GHSA-438q-jx8f-cccv · Severity: medium · Ecosystem: rust — Zebra Vulnerable to Allocation Amplification in Inbound Network Deserializers

Affected software / configurations for CVE-2026-44500

Vendor Product Version Raw CPE
zfnd zebra-chain < 7.0.0 cpe:2.3:a:zfnd:zebra-chain:*:*:*:*:*:rust:*:*
zfnd zebra-network < 6.0.0 cpe:2.3:a:zfnd:zebra-network:*:*:*:*:*:rust:*:*
zfnd zebrad < 4.4.0 cpe:2.3:a:zfnd:zebrad:*:*:*:*:*:rust:*:*

References for CVE-2026-44500

cvelogic Threat Intelligence