CVE-2026-97688

See a problem?
Please try reporting it to the source first.
Source
https://cve.org/CVERecord?id=CVE-2026-97688
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-97688.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-97688
Aliases
Downstream
BELL (1)
CGA (365)
CLEANSTART (4)
DEBIAN (1)
ECHO (1)
MINI (32)
openSUSE (3)
RHSA (1)
SUSE (4)
UBUNTU (1)
Related
openSUSE (3)
SUSE (4)
Published
2026-09-29T15:32:17Z
Modified
2026-10-21T02:30:37Z
Severity
  • 6.9 (Medium) CVSS_V4 - 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 CVSS Calculator
Summary
urllib3: Chunked Deflate streaming can enter an infinite loop
Details

urllib3 is an HTTP client library for Python. From 2.6.2 until 2.8.0, HTTPResponse.stream and HTTPResponse.read_chunked can enter an infinite loop because the Deflate decoder retains trailing bytes as unconsumed input after reaching end-of-stream and repeatedly decodes them without progress. The issue occurs when an untrusted server sends a chunked Deflate response whose decoded body exceeds a positive finite chunk size and whose encoded body has trailing bytes, specifically a response with Transfer-Encoding: chunked and Content-Encoding: deflate, content decoding enabled, and the positive finite amt=N streaming chunk size. The attack mechanism is that a malicious server returns a compressed chunked response with trailing bytes after the Deflate stream. The impact is excessive CPU usage and a request that does not complete, and network read timeouts do not interrupt the loop because no further socket read occurs. This issue is fixed in version 2.8.0.

Database specific 
{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-835"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/97xxx/CVE-2026-97688.json"
}
References

Affected packages

Git / github.com/urllib3/urllib3

Affected ranges

Type
GIT
Repo
https://github.com/urllib3/urllib3
Events
Introduced
83f8643ffb5b7f197457379148e2fa118ab0fcdc
Fixed
b1d30ab61fe0db8f11092805e8c5ac43e091064a
Fixed
ea2ad7b21a80da3632f80016526a18864586077f
Database specific
Show details 
{
    "extracted_events":  [
        {
            "cpe":  "cpe:2.3:a:python:urllib3:*:*:*:*:*:*:*:*",
            "range":  [
                {
                    "introduced":  "2.6.2"
                },
                {
                    "fixed":  "2.8.0"
                }
            ],
            "source":  "CPE_RANGE"
        },
        {
            "range":  [
                {
                    "fixed":  "ea2ad7b21a80da3632f80016526a18864586077f"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        },
        {
            "original_tag":  "2.8.0",
            "range":  [
                {
                    "fixed":  "b1d30ab61fe0db8f11092805e8c5ac43e091064a"
                }
            ],
            "source":  "REFERENCES_TAG"
        }
    ]
}

Affected versions

2.*
2.6.2
2.6.3
2.7.0

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-97688.json"