CVE-2026-39805

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Source
https://cve.org/CVERecord?id=CVE-2026-39805
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-39805.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-39805
Aliases
Published
2026-05-01T20:34:29.400Z
Modified
2026-07-15T01:48:58.604360394Z
Severity
  • 6.3 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N CVSS Calculator
Summary
CL.CL HTTP request smuggling via duplicate Content-Length in bandit
Details

Inconsistent Interpretation of HTTP Requests vulnerability in mtrudel bandit allows HTTP request smuggling via duplicate Content-Length headers.

'Elixir.Bandit.Headers':getcontentlength/1 in lib/bandit/headers.ex uses List.keyfind/3, which returns only the first matching header. When a request contains two Content-Length headers with different values, Bandit silently accepts it, uses the first value to read the body, and dispatches the remaining bytes as a second pipelined request on the same keep-alive connection. RFC 9112 ยง6.3 requires recipients to treat this as an unrecoverable framing error.

When Bandit sits behind a proxy that picks the last Content-Length value and forwards the request rather than rejecting it, an unauthenticated attacker can smuggle requests past edge WAF rules, path-based ACLs, rate limiting, and audit logging.

This issue affects bandit: before 1.11.0.

Database specific 
{
    "cwe_ids": [
        "CWE-444"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39805.json",
    "unresolved_ranges": [
        {
            "extracted_events": [
                {
                    "fixed": "f2ca636eb6df385219957e8934e9fc6efa1630d1"
                }
            ],
            "source": "AFFECTED_FIELD"
        }
    ],
    "cna_assigner": "EEF"
}
References

Affected packages

Git / github.com/mtrudel/bandit

Affected ranges

Type
GIT
Repo
https://github.com/mtrudel/bandit
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
e62619895d0d2584d7ffa57d43ef6f72437dfaff
Fixed
f2ca636eb6df385219957e8934e9fc6efa1630d1
Database specific 
{
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "1.11.0"
        }
    ],
    "source": [
        "DESCRIPTION",
        "REFERENCES"
    ]
}

Affected versions

0.*
0.1.0
0.1.1
0.2.0
0.2.1
0.2.2
0.2.3
0.3.0
0.3.1
0.3.2
0.3.3
0.3.4
0.3.5
0.3.6
0.3.7
0.3.8
0.3.9
0.4.0
0.4.1
0.4.10
0.4.2
0.4.3
0.4.4
0.4.5
0.4.6
0.4.7
0.4.8
0.4.9
0.5.0
0.5.1
0.5.10
0.5.11
0.5.2
0.5.3
0.5.4
0.5.5
0.5.6
0.5.7
0.5.8
0.5.9
0.6.0
0.6.1
0.6.10
0.6.11
0.6.2
0.6.3
0.6.4
0.6.5
0.6.6
0.6.7
0.6.8
0.6.9
0.7.0
0.7.1
0.7.2
0.7.3
0.7.4
0.7.5
0.7.6
0.7.7
1.*
1.0.0
1.0.0-pre.1
1.0.0-pre.10
1.0.0-pre.11
1.0.0-pre.12
1.0.0-pre.13
1.0.0-pre.14
1.0.0-pre.15
1.0.0-pre.16
1.0.0-pre.17
1.0.0-pre.18
1.0.0-pre.2
1.0.0-pre.3
1.0.0-pre.4
1.0.0-pre.5
1.0.0-pre.6
1.0.0-pre.7
1.0.0-pre.8
1.0.0-pre.9
1.1.0
1.1.1
1.1.2
1.1.3
1.10.0
1.10.1
1.10.2
1.10.3
1.10.4
1.2.0
1.2.3
1.3.0
1.4.0
1.4.1
1.4.2
1.5.0
1.5.1
1.5.2
1.5.3
1.5.4
1.5.5
1.5.6
1.5.7
1.6.0
1.6.1
1.6.10
1.6.11
1.6.2
1.6.3
1.6.4
1.6.5
1.6.6
1.6.7
1.6.8
1.6.9
1.7.0
1.8.0
1.9.0

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-39805.json"