EEF-CVE-2026-39805

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Source
https://cna.erlef.org/osv/EEF-CVE-2026-39805.html
Import Source
https://cna.erlef.org/osv/EEF-CVE-2026-39805.json
JSON Data
https://api.osv.dev/v1/vulns/EEF-CVE-2026-39805
Aliases
  • CVE-2026-39805
  • GHSA-c67r-gc9j-2qf7
Published
2026-05-01T20:34:29.400Z
Modified
2026-05-02T04:17:41.202Z
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

Summary

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 §6.3 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 
{
    "cpe_ids": [
        "cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:*"
    ],
    "capec_ids": [
        "CAPEC-33"
    ],
    "cwe_ids": [
        "CWE-444"
    ]
}
References
Credits
    • Peter Ullrich - FINDER
    • Mat Trudel - REMEDIATION_DEVELOPER
    • Jonatan Männchen - ANALYST

Affected packages

Hex / bandit

Package

Name
bandit
Purl
pkg:hex/bandit

Affected ranges

Type
SEMVER
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
1.11.0

Affected versions

0.*
0.1.0
0.1.1
0.2.0
0.2.1
0.2.2
0.2.3
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
0.4.2
0.4.3
0.4.4
0.4.5
0.4.6
0.4.7
0.4.8
0.4.9
0.4.10
0.5.0
0.5.1
0.5.2
0.5.3
0.5.4
0.5.5
0.5.6
0.5.7
0.5.8
0.5.9
0.5.10
0.5.11
0.6.0
0.6.1
0.6.2
0.6.3
0.6.4
0.6.5
0.6.6
0.6.7
0.6.8
0.6.9
0.6.10
0.6.11
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-pre.1
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
1.0.0-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
1.1.0
1.1.1
1.1.2
1.1.3
1.2.0
1.2.1
1.2.2
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
1.6.2
1.6.3
1.6.4
1.6.5
1.6.6
1.6.7
1.6.8
1.6.9
1.6.10
1.6.11
1.7.0
1.8.0
1.9.0
1.10.0
1.10.1
1.10.2
1.10.3
1.10.4

Database specific

source 
"https://cna.erlef.org/osv/EEF-CVE-2026-39805.json"

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
1.11.0

Database specific

source 
"https://cna.erlef.org/osv/EEF-CVE-2026-39805.json"