CVE-2025-13836CWE-400denial-of-service

CVE-2025-13836

High · published December 1, 2025

CVSS v3.1
7.5
EPSS
2%
Percentile
76.0
In the wild
Unconfirmed
What it is

⚠️ If no read amount is specified, a malicious server could trick your client into gulping down an excessive amount of data! 💥 Think of it like a restaurant giving you a bottomless drink without specifying a limit — you could end up drowning in soda! This vulnerability lets an attacker fill up your memory until it overflows, just like a never-ending soda fountain could overflow your table. An attacker could exploit this by causing your application to read massive amounts of data into memory, potentially leading to an out-of-memory (OOM) condition or even a denial-of-service (DoS) scenario. This could interrupt service and leave users frustrated, not to mention it can take a toll on your resources!

Put simply

Think of it like a restaurant giving you a bottomless drink without specifying a limit — you could end up drowning in soda! This vulnerability lets an attacker fill up your memory until it overflows, just like a never-ending soda fountain could overflow your table. This vulnerability occurs when reading an HTTP response without a specified read amount, defaulting to the Content-Length. If a malicious server controls this value, it can force the client to consume excessive data, leading to performance degradation or crashes.

What to do

An attacker could exploit this by causing your application to read massive amounts of data into memory, potentially leading to an out-of-memory (OOM) condition or even a denial-of-service (DoS) scenario. This could interrupt service and leave users frustrated, not to mention it can take a toll on your resources! To mitigate this issue, ensure you specify a read amount when handling HTTP responses. Also, consider implementing rate limiting or monitoring to detect unexpected large data reads. Always stay updated with security patches related to your server's HTTP handling if available. You've got this! With these steps in place, you'll keep your systems stable and secure. 🛡️

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.01631 · 76.0th percentile
Weakness
CWE-400 · Uncontrolled Resource Consumption
Published
2025-12-01T23:16Z
Affected products (7)
ProductVersionsFixed in
python/python< 3.10.203.10.20
python/python≥ 3.11.0, < 3.11.153.11.15
python/python≥ 3.12.0, < 3.12.133.12.13
python/python≥ 3.13.0, < 3.13.113.13.11
python/pythonall versions—
python/pythonall versions—
python/pythonall versions—
References (9)
EPSS history
Timeline
  • 01 DEC 18:02Z
    Excessive read buffering DoS in http.client
    cvelistv5