CVE-2026-55830

HIGHPre-NVD 8.38.3—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 87% 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
Trending — 3 sources updated this weekElevated
8.3
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 8.3Exploit: NoneExposed: 0

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

RestrictedPython is a tool that helps to define a subset of the Python language which allows to provide a program input into a trusted environment. Prior to 8.3, check_function_argument_names() rejected protected guard hook names for regular, variadic, and keyword-only arguments but omitted positional-only arguments, allowing __getattr__, _getitem_, _write_, or _print_ to be shadowed by a local parameter and bypass the embedding application's access policy. This issue is fixed in version 8.3.

CVSS v3
8.3
EG Score
8.3(medium)
EPSS
13.3%
KEV
Not listed

Published

July 8, 2026

Last Modified

July 10, 2026

Advisory Details (2)

Auto-updated Jul 8, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github.
github Patch Available🟡 PoC Available

RestrictedPython guard hooks can be shadowed via positional-only arguments · Advisory · zopefoundation/RestrictedPython · GitHub

https://github.com/zopefoundation/RestrictedPython/security/advisories/GHSA-ffg3-p8fm-mjx2
github_commit

commit 3737596ec9f2 (zopefoundation/RestrictedPython)

Fix landed in zopefoundation/RestrictedPython commit 3737596ec9f2 — awaiting tagged release

https://github.com/zopefoundation/RestrictedPython/commit/3737596ec9f28c34a073cc845bd2f4c0a80cb671

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 12× 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. 2026-07-11 22:34 UTCEG score recompute
  2. 2026-07-11 10:26 UTCEG score recompute
  3. 2026-07-11 08:27 UTCEPSS rescore
  4. 2026-07-11 08:27 UTCEPSS rescore
  5. 2026-07-10 22:17 UTCEG score recompute
  6. 2026-07-10 10:06 UTCEG score recompute
  7. 2026-07-09 21:57 UTCEG score recompute
  8. 2026-07-09 19:10 UTCEPSS rescore
  9. 2026-07-09 19:10 UTCEPSS rescore
  10. 2026-07-09 09:48 UTCEG score recompute
  11. 2026-07-08 21:39 UTCEG score recompute
  12. 2026-07-08 21:39 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-55830?
CVE-2026-55830 is a high vulnerability published on July 8, 2026. RestrictedPython is a tool that helps to define a subset of the Python language which allows to provide a program input into a trusted environment. Prior to 8.3, checkfunctionargumentnames() rejected protected guard hook names for regular, variadic, and keyword-only arguments but omitted…
When was CVE-2026-55830 disclosed?
CVE-2026-55830 was first published in the National Vulnerability Database on July 8, 2026, with the most recent update on July 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55830 actively exploited?
CVE-2026-55830 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 13.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-55830?
CVE-2026-55830 has a CVSS v3 base score of 8.3 (NVD).
How do I remediate CVE-2026-55830?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55830, 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.

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