Cyber Resilience

CVE-2025-6075

DoS in Python ≤ 3.9.0

Published
31 October 2025
Modified
04 February 2026
Patch / advisory
CVSS Score v4 1.8
Click a component to see what it means
Raw vectorCVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0014 4th percentile
Risk Priority 15 floored blend · peak EPSS

Summary

CVE-2025-6075 is a low-severity Uncontrolled Resource Consumption (CWE-400) vulnerability in Python Python. Its CVSS base score is 1.8 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SC-5 (Denial-of-service Protection) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

If the value passed to os.path.expandvars() is user-controlled a performance degradation is possible when expanding environment variables.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

CWE-400 resource exhaustion via untrusted input to expandvars enables application-layer DoS through crafted input causing performance degradation.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-15308Same product: Python Python
CVE-2026-4224Same product: Python Python
CVE-2025-13837Same product: Python Python
CVE-2025-13836Same product: Python Python
CVE-2024-7592Same product: Python Python
CVE-2025-13462Same product: Python Python
CVE-2023-33595Same product: Python Python
CVE-2026-3644Same product: Python Python
CVE-2026-4519Same product: Python Python
CVE-2026-6019Same product: Python Python

Affected Assets

python
python
3.15.0 · ≤ 3.9.0 · 3.13.1 — 3.13.11 · 3.14.0 — 3.14.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-10 Information Input Validation
  • SC-5 Denial-of-service Protection
Detect
Catch it (NIST detect / respond)
  • SI-4 System Monitoring
Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires validation and sanitization of untrusted input before it reaches os.path.expandvars, blocking the crafted values that trigger uncontrolled expansion.

prevent

Limits the effects of resource-consumption attacks (CWE-400) that produce performance degradation from malicious environment-variable strings.

detect

Enables monitoring of CPU/memory usage anomalies that would indicate an ongoing algorithmic-complexity attack against expandvars.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.IR-04 mostly match
prevents

Explicitly requires monitoring and maintaining resource capacity, directly addressing uncontrolled consumption to preserve availability.

DE.CM-09 partial match
prevents

Continuous monitoring of computing resources can detect resource exhaustion but does not itself enforce allocation limits.

PR.IR-03 partial match
prevents

Resilience mechanisms such as avoiding single points of failure indirectly reduce impact of resource exhaustion.

PR.PS-01 partial match
prevents

Hardened configuration baselines can include resource quotas and limits that constrain consumption.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Resource-utilization monitoring and alerting on bottlenecks or overloads limits the impact of denial-of-service or resource-exhaustion attacks.

prevents

By continuously monitoring utilization, stress-testing peak loads, and maintaining documented plans to scale or throttle resources, the control directly limits an attacker’s ability to drive a system into uncontrolled resource exhaustion.

detects

Pre-agreed severity-based prioritization and resource allocation during incident triage reduce the likelihood that an attacker-induced resource exhaustion will overwhelm the organization before corrective action is taken.

mitigates

Business-continuity plans that include resource-management controls reduce the likelihood that an attacker can trigger uncontrolled resource consumption by forcing the system into a degraded or fallback state.

mitigates

Defining RTOs and capacity requirements for ICT services during business-impact analysis forces organizations to provision sufficient resources and throttling mechanisms, reducing the likelihood that an attacker can induce denial-of-service through uncontrolled resource consumption.

detects

Early notification of anomalous resource consumption or system malfunctions enables throttling or isolation before availability is lost.

References