CVE-2026-74899

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-17. a secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this weekElevated
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.8Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

openssl_encrypt versions before 1.4.0 contain a sandbox escape vulnerability in IsolatedPluginExecutor that exposes Python type objects in restricted exec() builtins. Attackers can traverse the Python class hierarchy via __class__.__mro__.__subclasses__() to access system functions and execute arbitrary OS commands.

CVSS v3
9.8
EG Score
9.8(high)
EG Risk
75(Attend)
EG Risk 75/100SSVC: Attend

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
Severity98% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
32%
KEV
Not listed

Published

August 17, 2026

Last Modified

August 18, 2026

Advisory Details (3)

Auto-updated Aug 18, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Path Traversal in MCP tool database_clean (RemoveUnusedAttributeView) leads to Arbitrary File Read (via history copy) and Arbitrary File Deletion, missed by the recent GHSA-7hm9-v7vf-7g4w fix · Advisory · siyuan-note/siyuan · GitHub

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-43jx-gxq4-jpjc
generic

openssl_encrypt before 1.4.0 Sandbox Escape via Type Hierarchy | Advisories | VulnCheck

https://www.vulncheck.com/advisories/openssl-encrypt-before-sandbox-escape-via-type-hierarchy
github Patch Available🟡 PoC Available

Plugin sandbox escape via Python type hierarchy traversal · Advisory · jahlives/openssl_encrypt · GitHub

https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-m25m-ggxg-239c

Vendor Advisories for CVE-2026-74899(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 36× in last 7d / 36× 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. 2026-08-21 05:39 UTCGHSA enrichment
  2. 2026-08-21 01:30 UTCEG score recompute
  3. 2026-08-21 01:30 UTCGHSA enrichment
  4. 2026-08-20 22:56 UTCEPSS rescore
  5. 2026-08-20 21:22 UTCGHSA enrichment
  6. 2026-08-20 17:14 UTCGHSA enrichment
  7. 2026-08-20 13:05 UTCGHSA enrichment
  8. 2026-08-20 08:50 UTCGHSA enrichment
  9. 2026-08-20 04:42 UTCGHSA enrichment
  10. 2026-08-20 00:33 UTCGHSA enrichment
  11. 2026-08-19 20:24 UTCEG score recompute
  12. 2026-08-19 20:24 UTCGHSA enrichment
  13. 2026-08-19 17:04 UTCEPSS rescore
  14. 2026-08-19 16:14 UTCGHSA enrichment
  15. 2026-08-19 12:02 UTCGHSA enrichment
  16. 2026-08-19 07:53 UTCGHSA enrichment
  17. 2026-08-19 03:44 UTCGHSA enrichment
  18. 2026-08-18 23:36 UTCGHSA enrichment
  19. 2026-08-18 19:27 UTCEG score recompute
  20. 2026-08-18 19:27 UTCGHSA enrichment
  21. 2026-08-18 15:18 UTCEG score recompute
  22. 2026-08-18 15:18 UTCGHSA enrichment
  23. 2026-08-18 14:51 UTCEG score recompute
  24. 2026-08-18 14:51 UTCGHSA enrichment
  25. 2026-08-18 13:49 UTCEPSS rescore
Show 11 more
  1. 2026-08-18 13:49 UTCEPSS rescore
  2. 2026-08-18 12:40 UTCGHSA enrichment
  3. 2026-08-18 08:32 UTCGHSA enrichment
  4. 2026-08-18 04:20 UTCGHSA enrichment
  5. 2026-08-18 00:09 UTCGHSA enrichment
  6. 2026-08-17 19:56 UTCGHSA enrichment
  7. 2026-08-17 15:47 UTCEG score recompute
  8. 2026-08-17 15:47 UTCGHSA enrichment
  9. 2026-08-17 11:38 UTCEG score recompute
  10. 2026-08-17 11:13 UTCEG score recompute
  11. 2026-08-17 11:12 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-74899?
CVE-2026-74899 is a critical vulnerability published on August 17, 2026. openssl_encrypt versions before 1.4.0 contain a sandbox escape vulnerability in IsolatedPluginExecutor that exposes Python type objects in restricted exec() builtins. Attackers can traverse the Python class hierarchy via class.mro.subclasses() to access system functions and execute arbitrary OS…
When was CVE-2026-74899 disclosed?
CVE-2026-74899 was first published in the National Vulnerability Database on August 17, 2026, with the most recent update on August 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-74899 actively exploited?
CVE-2026-74899 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 67.8% of all scored CVEs.
What is the CVSS score of CVE-2026-74899?
CVE-2026-74899 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-74899?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-74899, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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