CVE-2026-77401

MEDIUMPre-NVD 6.86.8—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 69% 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 week
6.8EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.8Exploit: None knownExposed: 0

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

Zope AccessControl provides a general security framework for use in Zope. Prior to 7.4, applications that allow untrusted users to create and execute AccessControl-controlled Python code do not safely guard str.format and str.format_map when those methods are reached through a str subclass. In both ImplPython.py and cAccessControl.c, Python formatting can recursively access attributes and subscriptions using unrestricted getattr and getitem behavior instead of the policy-restricted getattr and getitem operations. A controlled format string can therefore disclose objects reachable from values available to the formatting operation. This issue is fixed in version 7.4.

CVSS v3
6.8
EG Score
6.8(medium)
EG Risk
31(Track)
EG Risk 31/100SSVC: Track

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
Severity68% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
31%
KEV
Not listed

Published

September 16, 2026

Last Modified

September 16, 2026

Advisory Details (2)

Auto-updated Sep 16, 2026
Patch available. Sources: github, github_commit.
github_commit

commit f980450eea41 (zopefoundation/AccessControl)

Fix landed in zopefoundation/AccessControl commit f980450eea41 — awaiting tagged release

https://github.com/zopefoundation/AccessControl/commit/f980450eea416718be62847f34dfd51822938e43
github Patch Available

Information disclosure through Python string `format` and `format_map` functions · Advisory · zopefoundation/AccessControl · GitHub

https://github.com/zopefoundation/AccessControl/security/advisories/GHSA-pq59-9fq7-m886

Vendor Advisories for CVE-2026-77401(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 8× in last 7d / 8× 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. 2026-09-19 19:08 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-18 19:11 UTCEG score recompute
  4. 2026-09-16 19:25 UTCEG score recompute
  5. 2026-09-16 18:52 UTCEG score recompute
  6. 2026-09-16 15:20 UTCEG score recompute
  7. 2026-09-16 14:36 UTCEG score recompute
  8. 2026-09-16 14:35 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-77401?
CVE-2026-77401 is a medium vulnerability published on September 16, 2026. Zope AccessControl provides a general security framework for use in Zope. Prior to 7.4, applications that allow untrusted users to create and execute AccessControl-controlled Python code do not safely guard str.format and str.format_map when those methods are reached through a str subclass. In both…
When was CVE-2026-77401 disclosed?
CVE-2026-77401 was first published in the National Vulnerability Database on September 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-77401 actively exploited?
CVE-2026-77401 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 69.4% of all scored CVEs.
What is the CVSS score of CVE-2026-77401?
CVE-2026-77401 has a CVSS v3 base score of 6.8 (NVD).
How do I remediate CVE-2026-77401?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-77401, 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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