CVE-2021-32838
Regular Expression Denial of Service in flask-restx
HIGH
7.5
CVSS Score
Published: September 20, 2021 at 05:30 PM UTC
Updated: June 17, 2026 at 03:53 AM UTC
3 products affected across 3 vendorsFedoraFlask RestxFlask-RESTX
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Severity
HIGH7.5
Exploit prediction
EPSS 2%
Description
Flask-RESTX (pypi package flask-restx) is a community driven fork of Flask-RESTPlus. Flask-RESTX before version 0.5.1 is vulnerable to ReDoS (Regular Expression Denial of Service) in email_regex. This is fixed in version 0.5.1.
Affected
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
v < 0.5.1
Affected range stops below 0.5.1, so it looks safe — our inference, not a vendor statement
60%
v < 0.5.1
Affected range stops below 0.5.1, so it looks safe — our inference, not a vendor statement
Remediation
No guide yetNo remediation guidance has been written for this CVE yet. What the record does show:
Patch and advisory references
- https://github.com/python-restx/flask-restx/blob/fd99fe11a88531f5f3441a278f7020589f9d2cc0/flask_restx/inputs.py#L51
- https://github.com/python-restx/flask-restx/commit/bab31e085f355dd73858fd3715f7ed71849656da
- https://github.com/python-restx/flask-restx/issues/372
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5UCTFVDU3677B5OBGK4EF5NMUPJLL6SQ/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QUD6SWZLX52AAZUHDETJ2CDMQGEPGFL3/
References (7)
x_refsource_CONFIRMThird Party Advisory
Source: [email protected]
https://github.com/advisories/GHSA-3q6g-vf58-7m4gx_refsource_MISCPatchThird Party Advisory
Source: [email protected]
https://github.com/python-restx/flask-restx/blob/fd99fe11a88531f5f3441a278f7020589f9d2cc0/flask_restx/inputs.py#L51x_refsource_MISCPatchThird Party Advisory
Source: [email protected]
https://github.com/python-restx/flask-restx/commit/bab31e085f355dd73858fd3715f7ed71849656dax_refsource_MISCIssue TrackingPatchThird Party Advisory
Source: [email protected]
https://github.com/python-restx/flask-restx/issues/372Vendor Advisoryx_refsource_FEDORA
Source: [email protected]
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5UCTFVDU3677B5OBGK4EF5NMUPJLL6SQ/Vendor Advisoryx_refsource_FEDORA
Source: [email protected]
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QUD6SWZLX52AAZUHDETJ2CDMQGEPGFL3/x_refsource_MISCProductThird Party Advisory
Source: [email protected]
https://pypi.org/project/flask-restx/CVSS
7.5HIGHGitHub_M
- Attack Vector
- NETWORK
- Complexity
- LOW
- Privileges
- NONE
- User Interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality
- NONE
- Integrity
- NONE
- Availability
- HIGH
Vector?
Quick Info
StatusMODIFIED
CWE
CWE-400
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