CVE-2026-54567

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.6%, top 54% 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
Elevated
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 7.5Exploit: Elevated riskExposed: 0

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

Flask-Reuploaded provides file uploads for Flask. From 1.5.0 until 1.6.0, UploadSet.save(storage, name=...) in src/flask_uploads/flask_uploads.py applies lowercase_ext to the default upload path but uses the case-preserving extension helper for a caller-supplied name before extension_allowed evaluates an AllExcept denylist. An attacker who controls the name override can use a mixed-case dangerous extension to bypass a lowercase denylist and store the file in the served upload directory. Exploitation requires a denylist configuration, a user-influenced name override, and a deployment that resolves or executes extensions case-insensitively; pure allowlists remain protected and path containment is not bypassed. On an execution-capable upload directory, the stored file can execute with the web server's privileges and affect confidentiality, integrity, and availability. This issue is fixed in version 1.6.0.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
50(Track*)
EG Risk 50/100SSVC: 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
Severity75% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Watch closely — could escalate to Attend.
EPSS PROB
1%
EPSS %ILE
47%
KEV
Not listed

Published

July 17, 2026

Last Modified

September 16, 2026

Advisory Details (3)

Auto-updated Sep 14, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_pr, github_commit.
github_commit

commit 5ded76092429 (jugmac00/flask-reuploaded)

Fix landed in jugmac00/flask-reuploaded commit 5ded76092429 — awaiting tagged release

https://github.com/jugmac00/flask-reuploaded/commit/5ded76092429c6eb8a4af941b14fbde40a38fff4
github_pr

Fix extension issue

Fix merged in jugmac00/flask-reuploaded PR #186 on 2026-06-06 — awaiting tagged release

https://github.com/jugmac00/flask-reuploaded/pull/186
github Patch Available🟡 PoC Available

Extension-denylist bypass via case-folding asymmetry in name-override path (incomplete-fix variant of CVE-2026-27641) · Advisory · jugmac00/flask-reuploaded · GitHub

Affected: v1.5.0; this variant survives that fix)

https://github.com/jugmac00/flask-reuploaded/security/advisories/GHSA-937x-gpqr-72gg

Vendor Advisories for CVE-2026-54567(1)

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

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
flask-reuploaded0.3 ... 1.5.0 (11 versions)1.6.0—

Weakness Classification(2)

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. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 04:31 UTCEG score recompute
  3. 2026-09-17 19:31 UTCEPSS rescore
  4. 2026-09-16 17:11 UTCEG score recompute
  5. 2026-09-16 15:36 UTCEG score recompute
  6. 2026-09-16 14:08 UTCEPSS rescore
  7. 2026-09-16 05:15 UTCEPSS rescore
  8. 2026-09-14 18:38 UTCEG score recompute
  9. 2026-07-30 18:58 UTCEG score recompute
  10. 2026-07-26 11:17 UTCEG score recompute
  11. 2026-07-23 03:19 UTCEG score recompute
  12. 2026-07-17 21:00 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-54567?
CVE-2026-54567 is a high vulnerability published on July 17, 2026. Flask-Reuploaded provides file uploads for Flask. From 1.5.0 until 1.6.0, UploadSet.save(storage, name=...) in src/flaskuploads/flaskuploads.py applies lowercaseext to the default upload path but uses the case-preserving extension helper for a caller-supplied name before extensionallowed evaluates…
When was CVE-2026-54567 disclosed?
CVE-2026-54567 was first published in the National Vulnerability Database on July 17, 2026, with the most recent update 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-2026-54567 actively exploited?
CVE-2026-54567 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 53.4% of all scored CVEs.
What is the CVSS score of CVE-2026-54567?
CVE-2026-54567 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-54567?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-54567, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-54567

Explore →

Is Your Infrastructure Affected by CVE-2026-54567?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs