CVE-2026-52735: ZEBRA is a Zcash node written entirely in Rust

This month

CRITICAL 9.3REMOTE

CVE-2026-52735 is a critical-severity flaw (CVSS 9.3) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5.0, Zebra can accept a block that zcashd rejects because the P2SH signature-operation counter undercounts redeem scripts containing a disabled opcode followed by signature opcodes. In zebra-script/src/lib.rs, p2sh_input_sigop_count used the pure-Rust script::Code::sig_op_count path, whose try_fold parser stops at disabled opcodes such as OP_CODESEPARATOR and returns only the partial coun

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.3 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 58%)
CISA exploited list	No
Weakness	CWE-684
Published	2026-08-18
Last modified	2026-10-22

Publisher (CNA): GitHub, Inc.

Last updated 2026-10-22 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-08-18Published CVE record published
2026-10-22 22:10 UTCUpdated Record last modified

Exact fixes by distribution

Rust (Cargo) · zebra-script · FIXED · 7.0.0 · vulnerable: <= 6.0.1 · source

Set zebra-script >= 7.0.0 in Cargo.toml, then run: cargo update -p zebra-script

Rust (Cargo) · zebrad · FIXED · 4.5.0 · vulnerable: <= 4.4.1 · source

Set zebrad >= 4.5.0 in Cargo.toml, then run: cargo update -p zebrad

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-52735?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2026-52735 being exploited?

CVE-2026-52735 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-52735 affect?

CVE-2026-52735 affects affected software. Severity is critical (CVSS 9.3). ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5.0, Zebra can accept a block that zcashd rejects because the P2SH signature-operation counter undercounts redeem scripts containing a disabled opcode followed by signature opcodes.

How urgent is CVE-2026-52735?

Priority 48/100. Critical severity; Remotely exploitable, no login, no user action

References

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