CVE-2026-90616

HIGHPre-NVD 7.47.4—
EchelonGraph scoreHIGH confidence

Score 7.4 from GitHub Security Advisory (severity: HIGH) published 2026-09-12. a secondary CVSS source baseline 7.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
7.4EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.4Exploit: None knownExposed: 0

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

In Flatpak before 1.18.1, a malicious sandboxed app can obtain arbitrary read and write access to files on the host, which can be escalated to arbitrary code execution on the host, a different vulnerability than CVE-2026-76925. Flatpak creates a few app data directories (e.g., /var/cache, /var/data, /var/config, and /var/tmp) in every sandbox on every app launch where, in some cases, components of the path are attacker-controlled. Missing symlink protection can redirect the directories. Some of these directories are bind-mounted by Flatpak by passing the path (e.g., /home/user/.var/app/APP_ID/cache/tmp), which contains attacker-controlled directories (tmp) to bwrap --bind SRC DST. bwrap passes the path on to the kernel, which then follows symlinks. A malicious symlink can point to arbitrary locations on the host and it will become mounted inside the sandbox.

CVSS v3
7.4
EG Score
7.4(high)
EG Risk
33(Track)
EG Risk 33/100SSVC: 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
Severity74% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
6%
KEV
Not listed

Published

September 12, 2026

Last Modified

September 14, 2026

Advisory Details (2)

Auto-updated Sep 12, 2026
Patch available. Sources: github.
generic

oss-security - Flatpak 1.18.1 fixes multiple vulnerabilities

https://www.openwall.com/lists/oss-security/2026/08/11/9
github Patch Available

Flatpak sandbox escape with full host filesystem access · Advisory · flatpak/flatpak · GitHub

Affected: version 1.18.1 by commit:

https://github.com/flatpak/flatpak/security/advisories/GHSA-8688-9x26-hhxj

Vendor Advisories for CVE-2026-90616(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 29× in last 7d / 29× 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 00:52 UTCEG score recompute
  2. 2026-09-19 00:51 UTCGHSA enrichment
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-18 12:22 UTCGHSA enrichment
  5. 2026-09-17 23:52 UTCEG score recompute
  6. 2026-09-17 23:52 UTCGHSA enrichment
  7. 2026-09-17 19:32 UTCEPSS rescore
  8. 2026-09-17 10:16 UTCGHSA enrichment
  9. 2026-09-16 21:46 UTCEG score recompute
  10. 2026-09-16 21:46 UTCGHSA enrichment
  11. 2026-09-16 14:09 UTCEPSS rescore
  12. 2026-09-16 09:17 UTCEG score recompute
  13. 2026-09-16 09:17 UTCGHSA enrichment
  14. 2026-09-16 05:15 UTCEPSS rescore
  15. 2026-09-15 20:48 UTCGHSA enrichment
  16. 2026-09-15 07:50 UTCEG score recompute
  17. 2026-09-15 07:50 UTCGHSA enrichment
  18. 2026-09-15 03:12 UTCEPSS rescore
  19. 2026-09-14 19:21 UTCEG score recompute
  20. 2026-09-14 19:21 UTCGHSA enrichment
  21. 2026-09-14 18:40 UTCEG score recompute
  22. 2026-09-14 18:40 UTCGHSA enrichment
  23. 2026-09-14 09:59 UTCGHSA enrichment
  24. 2026-09-13 21:30 UTCGHSA enrichment
  25. 2026-09-13 09:01 UTCEG score recompute
Show 4 more
  1. 2026-09-13 09:00 UTCGHSA enrichment
  2. 2026-09-12 20:32 UTCEG score recompute
  3. 2026-09-12 20:12 UTCEG score recompute
  4. 2026-09-12 20:12 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-90616?
CVE-2026-90616 is a high vulnerability published on September 12, 2026. In Flatpak before 1.18.1, a malicious sandboxed app can obtain arbitrary read and write access to files on the host, which can be escalated to arbitrary code execution on the host, a different vulnerability than CVE-2026-76925. Flatpak creates a few app data directories (e.g., /var/cache,…
When was CVE-2026-90616 disclosed?
CVE-2026-90616 was first published in the National Vulnerability Database on September 12, 2026, with the most recent update on September 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-90616 actively exploited?
CVE-2026-90616 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 93.6% of all scored CVEs.
What is the CVSS score of CVE-2026-90616?
CVE-2026-90616 has a CVSS v3 base score of 7.4 (NVD).
How do I remediate CVE-2026-90616?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-90616, 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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