CVE-2026-61541CWE-770denial-of-service

CVE-2026-61541

published September 22, 2026

CVSS
6.9
EPSS
0%
Percentile
36.0
In the wild
Unconfirmed
What it is

Zapros, a Python HTTP client, prior to version 0.14.0 is vulnerable to denial of service when an application requests content from an untrusted server, or follows a redirect to one, because a malicious response containing an excessive number of chained `Content-Encoding` values causes Zapros to construct a deeply nested decompression chain that consumes excessive resources. Version 0.14.0 patches the vulnerability by limiting responses to five content-encoding layers and raising `DecodingError` when that limit is exceeded. As a workaround, applications can add response middleware that inspects the `Content-Encoding` header and rejects responses containing more than a safe number of encoding layers.

The record
Technical detail
CVSS
6.9 · NONE
CVSS v4.0
6.9 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
EPSS
0.00428 · 36.0th percentile
Weakness
CWE-770 · Allocation of Resources Without Limits or Throttling
Published
2026-09-22T02:16Z
References (1)
EPSS history
Timeline
  • 23 SEP 03:47Z
    EPSS moved — → 0%
    epss
  • 21 SEP 21:21Z
    Zapros has an Unbounded Content-Encoding decompression chain that allows denial of service
    cvelistv5