CVE-2026-52735

CRITICALPre-NVD 9.39.3—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 78% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
9.3EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 9.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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 count accumulated before the error. The zcashd reference implementation continues static signature-operation counting through disabled opcodes, so an attacker can broadcast P2SH spends that Zebra counts below MAX_BLOCK_SIGOPS while zcashd counts above the 20,000-operation limit. If a Zebra miner includes those transactions, Zebra validators accept the block while zcashd validators reject it, creating a consensus chain split that affects network integrity and availability without requiring the attacker to produce a block. This issue is fixed in version 4.5.0.

CVSS v3
9.3
EG Score
9.3CRITICALmedium confidence
EG Risk
57
EG Risk 57/100

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity93% × 45%
Exploitation0% × 40%
Automatability100% × 15%
EPSS PROB
0.5%
EPSS %ILE
41st
KEV
Not listed

Published

July 2, 2026

Last Modified

September 9, 2026

Advisory Details (3)

Auto-updated Oct 3, 2026
Patch available. Sources: github_commit, github_release, github.
githubMentions a patch (unverified)

Consensus divergence via P2SH sigop undercount in pure-Rust disabled-opcode parser · Advisory · ZcashFoundation/zebra · GitHub

https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-gf9r-m956-97qx
github_release Patch Available

Zebra 4.5.0

Patch available: ZcashFoundation/zebra v4.5.0

https://github.com/ZcashFoundation/zebra/releases/tag/v4.5.0
github_commit

commit 1440b43ca7df (ZcashFoundation/zebra)

Fix landed in ZcashFoundation/zebra commit 1440b43ca7df — awaiting tagged release

https://github.com/ZcashFoundation/zebra/commit/1440b43ca7df59aca948090d45117557b217a6cd

Vendor Advisories for CVE-2026-52735(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(2 across 1 ecosystem)
crates.io(2)
PackageVulnerable rangeFix by version rangeDependents
zebrad—
  • every version up to 4.5.0: fixed in 4.5.0
—
zebra-script—
  • every version up to 7.0.0: fixed in 7.0.0
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 7× in last 7d / 28× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-09 20:07 UTCEPSS rescore
  2. 2026-10-08 17:12 UTCEPSS rescore
  3. 2026-10-07 23:48 UTCEPSS rescore
  4. 2026-10-06 15:18 UTCEPSS rescore
  5. 2026-10-05 17:43 UTCEPSS rescore
  6. 2026-10-04 23:22 UTCEPSS rescore
  7. 2026-10-03 14:26 UTCEPSS rescore
  8. 2026-10-02 17:56 UTCEPSS rescore
  9. 2026-10-01 19:50 UTCEPSS rescore
  10. 2026-09-30 15:03 UTCEPSS rescore
  11. 2026-09-29 15:22 UTCEPSS rescore
  12. 2026-09-28 13:51 UTCEPSS rescore
  13. 2026-09-27 13:48 UTCEPSS rescore
  14. 2026-09-26 15:59 UTCEPSS rescore
  15. 2026-09-26 00:27 UTCEPSS rescore
  16. 2026-09-23 17:53 UTCEPSS rescore
  17. 2026-09-23 06:38 UTCEG score recompute
  18. 2026-09-20 20:16 UTCEPSS rescore
  19. 2026-09-18 19:28 UTCEPSS rescore
  20. 2026-09-18 06:14 UTCEG score recompute
  21. 2026-09-16 14:08 UTCEPSS rescore
  22. 2026-09-16 05:15 UTCEPSS rescore
  23. 2026-09-13 17:43 UTCEG score recompute
  24. 2026-09-13 16:47 UTCEPSS rescore
  25. 2026-09-13 08:59 UTCEG score recompute
Show 39 more
  1. 2026-09-12 14:15 UTCEG score recompute
  2. 2026-09-11 14:53 UTCEPSS rescore
  3. 2026-09-10 09:35 UTCEPSS rescore
  4. 2026-09-09 22:59 UTCEG score recompute
  5. 2026-09-08 22:01 UTCEPSS rescore
  6. 2026-09-07 16:01 UTCEPSS rescore
  7. 2026-09-06 14:19 UTCEG score recompute
  8. 2026-09-06 13:47 UTCEPSS rescore
  9. 2026-09-05 23:53 UTCEG score recompute
  10. 2026-09-04 05:06 UTCEPSS rescore
  11. 2026-09-02 14:12 UTCEPSS rescore
  12. 2026-09-01 13:54 UTCEPSS rescore
  13. 2026-09-01 04:40 UTCEPSS rescore
  14. 2026-08-30 20:59 UTCEG score recompute
  15. 2026-08-30 19:17 UTCEPSS rescore
  16. 2026-08-30 11:22 UTCEG score recompute
  17. 2026-08-30 01:22 UTCEPSS rescore
  18. 2026-08-28 21:41 UTCEPSS rescore
  19. 2026-08-27 22:15 UTCEG score recompute
  20. 2026-08-26 14:46 UTCEPSS rescore
  21. 2026-08-25 13:49 UTCEPSS rescore
  22. 2026-08-24 14:23 UTCEG score recompute
  23. 2026-08-24 10:16 UTCEG score recompute
  24. 2026-08-23 03:39 UTCEG score recompute
  25. 2026-08-23 00:19 UTCEPSS rescore
  26. 2026-08-22 01:27 UTCEG score recompute
  27. 2026-08-21 23:49 UTCEPSS rescore
  28. 2026-08-21 00:36 UTCEG score recompute
  29. 2026-08-20 22:55 UTCEPSS rescore
  30. 2026-08-20 04:02 UTCEG score recompute
  31. 2026-08-19 17:04 UTCEPSS rescore
  32. 2026-08-18 20:25 UTCEG score recompute
  33. 2026-08-18 19:54 UTCEG score recompute
  34. 2026-08-18 19:29 UTCEG score recompute▲ 9.30
  35. 2026-08-18 19:29 UTCMITRE cvelistV5CVSS v3 → 9.3 · CVSS v4 → 9.3
  36. 2026-08-01 17:17 UTCEG score recompute
  37. 2026-07-26 13:03 UTCEG score recompute
  38. 2026-07-23 03:19 UTCEG score recompute
  39. 2026-07-02 20:07 UTCEG score recompute

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Frequently asked(5)

What is CVE-2026-52735?
CVE-2026-52735 is a critical vulnerability published on July 2, 2026. 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, p2shinputsigopcount used the…
When was CVE-2026-52735 disclosed?
CVE-2026-52735 was first published on July 2, 2026, with the most recent update on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-52735 actively exploited?
CVE-2026-52735 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (41st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-52735?
CVE-2026-52735 has a CVSS base score of 9.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-52735?
A fix for CVE-2026-52735 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-52735 are linked in the Vendor Advisories panel on this page.

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