CVE-2026-61652 (GCVE-0-2026-61652)

Vulnerability from cvelistv5 – Published: 2026-09-21 21:13 – Updated: 2026-09-21 21:13
VLAI
Title
Zapros: Streaming decoders ignored the requested chunk size, allowing a single compressed response chunk to allocate unbounded memory (decompression bomb)
Summary
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.
Severity
8.7 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CWE
  • CWE-770 - Allocation of Resources Without Limits or Throttling
Assigner
References
Impacted products
Vendor Product Version CPE status
kap-sh zapros Affected: < 0.14.0
guessed Create a notification for this product.
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        }
      ],
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        "discovery": "UNKNOWN"
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      "title": "Zapros: Streaming decoders ignored the requested chunk size, allowing a single compressed response chunk to allocate unbounded memory (decompression bomb)"
    }
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  "cveMetadata": {
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    "cveId": "CVE-2026-61652",
    "datePublished": "2026-09-21T21:13:26.969Z",
    "dateReserved": "2026-07-10T18:25:21.466Z",
    "dateUpdated": "2026-09-21T21:13:26.969Z",
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          }
        ],
        "id": "CVE-2026-61652",
        "lastModified": "2026-09-21T22:16:57.680",
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                "Recovery": "NOT_DEFINED",
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                "integrityRequirement": "NOT_DEFINED",
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                "modifiedAttackRequirements": "NOT_DEFINED",
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                "privilegesRequired": "NONE",
                "providerUrgency": "NOT_DEFINED",
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                "subConfidentialityImpact": "NONE",
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                "valueDensity": "NOT_DEFINED",
                "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
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                "vulnAvailabilityImpact": "HIGH",
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                "vulnIntegrityImpact": "NONE",
                "vulnerabilityResponseEffort": "NOT_DEFINED"
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    }
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}



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