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CVE Record

CVE-2021-29063: A Regular Expression Denial of Service (ReDOS) vulnerability was discovered in Mpmath v1.0.0 through v1.2.1...

A Regular Expression Denial of Service (ReDOS) vulnerability was discovered in Mpmath v1.0.0 through v1.2.1 when the mpmathify function is called.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2021-29063 is a denial-of-service flaw in Python's mpmath library. If an application uses affected mpmath versions and sends untrusted input into mpmathify, crafted input may consume excessive processing time and slow or stop the service.

Executive priority

Handle as a dependency hygiene and service availability issue. Prioritize internet-facing or API-exposed applications that parse user-supplied math expressions. Broader emergency response is not supported by the provided evidence.

Technical view

The CVE describes Regular Expression Denial of Service in mpmath v1.0.0 through v1.2.1 when mpmathify is called. The bundle references an upstream commit, mpmath 1.3.0, Fedora advisories, and a public PoC reference. No CVSS or CWE is provided.

Likely exposure

Exposure is limited to systems using mpmath 1.0.0 through 1.2.1 where untrusted strings can reach mpmathify. Internal-only math code without attacker-controlled input is lower risk. Fedora package users should verify fixed package status through the cited advisories.

Exploitation context

CISA KEV status is false, and the provided sources do not show active exploitation. A public PoC reference is listed, so defenders should treat the behavior as publicly known while avoiding assumptions about real-world exploitation.

Researcher notes

Evidence is incomplete: no CVSS, CWE, CPEs, or exploit-in-the-wild signal are provided. Some listed references appear unrelated to mpmath, so rely on the CVE text, mpmath commit/release, Fedora advisories, and PoC reference for scoping.

Mitigation direction

  • Inventory applications and dependencies for mpmath versions 1.0.0 through 1.2.1.
  • Upgrade mpmath beyond the affected range, checking mpmath 1.3.0 and vendor guidance.
  • Apply relevant Fedora package updates where Fedora packages are used.
  • Restrict untrusted input from reaching mpmathify until upgrades are complete.
  • Add input length and timeout controls around exposed parsing paths.

Validation and detection

  • Confirm dependency manifests and runtime environments no longer use affected mpmath versions.
  • Search application code for mpmathify calls reachable from user-controlled input.
  • Review production telemetry for unusual CPU saturation around math parsing endpoints.
  • Verify Fedora hosts include the advisory updates where applicable.
  • Run regression tests for legitimate mpmathify use after upgrading.
Prepared
Confidence
medium
Sources
8

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
10Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

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