CVE-2026-96276

CRITICALPre-NVD 9.89.8
EchelonGraph scoreLOW confidence

This critical-severity CVE scores 9.8 under CISA-ADP (Vulnrichment) CVSS v3.1 (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). 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: cisa-adp
Trending — 3 sources updated this week
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 9.8Exploit: None knownExposed: 0

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

If a malicious SDK container declares an extension point with a crafted directory path, and a developer runs flatpak build-init --writable-sdk --sdk-extension with that SDK, attacker-chosen files could be written outside the working directory, since the target path is resolved via a function that allows .. traversal.

CVSS v3
9.8
EG Score
9.8(low)
EG Risk
59(Track)
EG Risk 59/100SSVC: 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
Severity98% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
—
EPSS %ILE
—
KEV
Not listed

Published

September 23, 2026

Last Modified

September 23, 2026

Advisory Details (3)

Auto-updated Sep 23, 2026
Patch available. Sources: github, redhat.
github Patch Available

CVE-2026-96276: Arbitrary write in host context via `flatpak build-init` · Advisory · flatpak/flatpak · GitHub

Affected: version 1.18.1 by commits:

https://github.com/flatpak/flatpak/security/advisories/GHSA-8qxj-x646-phcm
redhat

Bug Access Denied

https://bugzilla.redhat.com/show_bug.cgi?id=2539418
redhat Patch Available

CVE-2026-96276 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a

https://access.redhat.com/security/cve/CVE-2026-96276

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 5× in last 7d / 5× 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. 2026-09-23 15:44 UTCEG score recompute▲ 9.80
  2. 2026-09-23 15:44 UTCMITRE cvelistV5CVSS v3 → 9.8 · severity → CRITICAL
  3. 2026-09-23 15:17 UTCNVD update
  4. 2026-09-23 15:14 UTCEG score recompute
  5. 2026-09-23 15:14 UTCMITRE cvelistV5first tracked

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Frequently asked(4)

What is CVE-2026-96276?
CVE-2026-96276 is a critical vulnerability published on September 23, 2026. If a malicious SDK container declares an extension point with a crafted directory path, and a developer runs flatpak build-init --writable-sdk --sdk-extension with that SDK, attacker-chosen files could be written outside the working directory, since the target path is resolved via a function that…
When was CVE-2026-96276 disclosed?
CVE-2026-96276 was first published in the National Vulnerability Database on September 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-96276?
CVE-2026-96276 has a CVSS v3.1 base score of 9.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-96276?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-96276, 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

Explore the affected products and dependency analysis for CVE-2026-96276

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