CVE-2026-27641

Q: How do I fix CVE-2026-27641?

Upgrade flask-reuploaded to 1.5.0 or later.

Q: Is CVE-2026-27641 being actively exploited?

Not that we know of. CVE-2026-27641 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 1.0% is the estimated probability that it will be exploited in the next 30 days. That is higher than 61% of all scored CVEs.

Q: How severe is CVE-2026-27641?

CVE-2026-27641 has a CVSS v3 base score of 9.8, rated critical. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

Q: What does CVE-2026-27641 affect?

Published advisories record a fix for flask-reuploaded (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

CRITICAL

9.8

CVSS v3

NVD

Description

Flask-Reuploaded provides file uploads for Flask. A critical path traversal and extension bypass vulnerability in versions prior to 1.5.0 allows remote attackers to achieve arbitrary file write and remote code execution through Server-Side Template Injection (SSTI). Flask-Reuploaded has been patched in version 1.5.0. Some workarounds are available. Do not pass user input to the `name` parameter, use auto-generated filenames only, and implement strict input validation if `name` must be used.

CWE-1336 CWE-22Path Traversal

How to fix

Remediation Available

flask-reuploadedNVD

Affected:< 1.5.0Fixed in:1.5.0CVE-2026-27641derived from NVD

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploit Intelligence

1.05%probability of exploitation in 30 days

61stpercentile

Moderate risk: more likely to be exploited than 61% of all known CVEs.

References

Patch2

Exploit1

github.com

Related Vulnerabilities

Other CWE-1336 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2024-4040	Critical	9.8	100%	KEV	Fix
CVE-2024-23692	Critical	9.8	99%	KEV + Ransom	-
CVE-2025-47916	Critical	10.0	85%	-	Fix
CVE-2024-32651	Critical	10.0	84%	-	-
CVE-2022-25813	High	7.5	67%	-	Fix
CVE-2025-34300	Unscored	-	51%	-	-

Common questions

How do I fix CVE-2026-27641?

Upgrade flask-reuploaded to 1.5.0 or later.

Is CVE-2026-27641 being actively exploited?

Not that we know of. CVE-2026-27641 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 1.0% is the estimated probability that it will be exploited in the next 30 days. That is higher than 61% of all scored CVEs.

How severe is CVE-2026-27641?

CVE-2026-27641 has a CVSS v3 base score of 9.8, rated critical. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-27641 affect?

Published advisories record a fix for flask-reuploaded (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

Embed a live status badge for CVE-2026-27641

Markdown

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-02-27.