CVE-2026-61652

HighCVSS 8.7

Published: 21/09/2026(UTC)Updated: 24/09/2026(UTC)Translated: 22/09/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.44%

35th percentile - higher than 35% of all known CVEs

Summary

Risk Assessment

The risk includes the possibility of memory exhaustion on the server or application, leading to crashes and service disruptions.

Recommendation

Upgrade Zapros to version 0.14.0 or later, and in the meantime apply workarounds such as manual decompression with size limits or sending Accept-Encoding: identity.

Other vulnerabilities in Zapros

CVE-2026-61541Medium
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.

Original NVD description (English source)

Zapros, a Python HTTP client, prior to version 0.14.0 is vulnerable to denial of service via memory exhaustion. The issue affects all callers who streamed compressed responses relying on the chunk size — explicit (`iter_bytes(chunk_size=...)`) or the default — to bound memory. The decoder ignored that bound, so a chunk could be far larger than requested and a single compressed response could overflow memory. Version 0.14.0 contains a patch. Some workarounds are available. Read the still-compressed body with `Response.iter_raw()` / `Response.async_iter_raw()`, which bypass the built-in decoders, and decompress it yourself with an explicit output-size bound (e.g. `zlib`'s `max_length`), aborting once a configured limit is exceeded. Where feasible, send `Accept-Encoding: identity` to disable response compression so bodies are not decompressed client-side. Avoid decoding response bodies from untrusted servers.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS