How severe is CVE-2025-13836?

CVE-2025-13836 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2025-13836 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-13836?

CVE-2025-13836 primarily affects Python. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2025-13836?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2025-13836 have an EU (EUVD) identifier?

Yes. CVE-2025-13836 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-200070.

When was CVE-2025-13836 published?

CVE-2025-13836 was published on 2025-12-01 and last updated on 2026-06-17.

CVE-2025-13836

CVE-2025-13836 is a high-severity vulnerability in Python with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-400.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 6.3
EPSS exploit prediction: 2% (72nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-200070
Weakness: CWE-400
Affected product: Python
Published: 2025-12-01
Last modified: 2026-06-17

Description

When reading an HTTP response from a server, if no read amount is specified, the default behavior will be to use Content-Length. This allows a malicious server to cause the client to read large amounts of data into memory, potentially causing OOM or other DoS.

Frequently asked questions

What is CVE-2025-13836?: When reading an HTTP response from a server, if no read amount is specified, the default behavior will be to use Content-Length. This allows a malicious server to cause the client to read large amounts of data into memory, potentially causing OOM or other DoS.
How severe is CVE-2025-13836?: CVE-2025-13836 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-13836 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-13836?: CVE-2025-13836 primarily affects Python. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-13836?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-13836 have an EU (EUVD) identifier?: Yes. CVE-2025-13836 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-200070.
When was CVE-2025-13836 published?: CVE-2025-13836 was published on 2025-12-01 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:python:python:*:*:*:*:*:*:*:*
cpe:2.3:a:python:python:3.14.0:-:*:*:*:*:*:*
cpe:2.3:a:python:python:3.15.0:alpha1:*:*:*:*:*:*
cpe:2.3:a:python:python:3.15.0:alpha2:*:*:*:*:*:*

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Threat intelligence

Threat-intel indicators referencing this CVE:

49.229.102.187 (ipv4-addr)
203.192.232.180 (ipv4-addr)
177.53.215.134 (ipv4-addr)
149.86.233.213 (ipv4-addr)
141.109.168.26 (ipv4-addr)
141.109.168.107 (ipv4-addr)
125.212.235.194 (ipv4-addr)
120.28.109.188 (ipv4-addr)