{"cve":"CVE-2026-61541","nvd":{"published":"2026-09-21T22:16:57.527","modified":"2026-09-30T17:32:07.107","status":"Deferred","description":"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.","cvss_v4":{"vector":"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","score":6.9},"cvss_v3":null,"cwes":["CWE-770"],"references":["https://github.com/kap-sh/zapros/security/advisories/GHSA-5vjj-2r48-q622"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:55:23.253742848+00:00"},"epss":{"cve":"CVE-2026-61541","score":0.00428,"percentile":0.36756,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-5vjj-2r48-q622","url":"https://osv.dev/vulnerability/GHSA-5vjj-2r48-q622","summary":"Zapros has an Unbounded Content-Encoding decompression chain that allows denial of service","modified":"2026-10-01T17:56:21.759535591Z","packages":[{"ecosystem":"PyPI","name":"zapros","purl":"pkg:pypi/zapros","ranges":["<0.14.0"],"fixed":["0.14.0"]}]},{"id":"PYSEC-2026-4181","url":"https://osv.dev/vulnerability/PYSEC-2026-4181","summary":"Zapros has an Unbounded Content-Encoding decompression chain that allows denial of service","modified":"2026-10-01T17:45:18.544159815Z","packages":[{"ecosystem":"PyPI","name":"zapros","purl":"pkg:pypi/zapros","ranges":["<0.14.0"],"fixed":["0.14.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}