CVE-2026-59980

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Source
https://cve.org/CVERecord?id=CVE-2026-59980
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-59980.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-59980
Aliases
Downstream
CGA (6)
CLEANSTART (2)
DEBIAN (1)
ECHO (1)
MGASA (1)
MINI (2)
OESA (4)
openSUSE (2)
SUSE (3)
UBUNTU (1)
Related
openSUSE (2)
SUSE (3)
Published
2026-09-23T22:07:35Z
Modified
2026-10-28T02:31:00Z
Severity
  • 6.3 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N CVSS Calculator
Summary
hpack: Unbounded variable integer decoding can cause run-away computation on malformed input
Details

hpack is an HTTP/2 Header Encoding for Python. Prior to version 4.2.0, unbounded variable integer decoding can cause run-away computation on malformed input leading to O(n^2) runtime, effectively blocking further processing with large enough unsanitized input. A fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation. As a workaround, sanitize input to hpack decoder for long sequences of 0xFF values to prevent malicious use.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-400"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59980.json"
}
References

Affected packages

Git / github.com/python-hyper/hpack

Affected ranges

Type
GIT
Repo
https://github.com/python-hyper/hpack
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
d05cff4cd462658847f67c48700aab40b2ba8cf1
Fixed
8cfb02c547740e16dbfe7aba77bad84b297cec2c
Database specific
Show details 
{
    "extracted_events": [
        {
            "range": [
                {
                    "introduced": "0"
                },
                {
                    "fixed": "4.2.0"
                }
            ],
            "source": "AFFECTED_FIELD",
            "strategy": "StringRangeExpression"
        },
        {
            "range": [
                {
                    "fixed": "8cfb02c547740e16dbfe7aba77bad84b297cec2c"
                }
            ],
            "source": "REFERENCES_COMMIT"
        }
    ]
}

Affected versions

v1.*
v1.0.0
v1.0.1
v1.1.0
v2.*
v2.0.0
v2.0.1
v2.1.0
v2.1.1
v2.2.0
v2.3.0
v3.*
v3.0.0
v4.*
v4.0.0
v4.1.0

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-59980.json"