CVE-2026-70399

Source
https://cve.org/CVERecord?id=CVE-2026-70399
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-70399.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-70399
Aliases
Downstream
Published
2026-09-01T14:33:05.717Z
Modified
2026-09-03T03:48:16.552513857Z
Severity
  • 8.7 (High) CVSS_V4 - 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 CVSS Calculator
Summary
httpd does not enforce the documented default max_clients connection limit
Details

Allocation of Resources Without Limits or Throttling vulnerability in Erlang/OTP inets httpd allows an unauthenticated remote attacker to cause denial of service by opening and holding open a large number of connections. The max_clients option is documented to default to 150, and the inets hardening guide presents that limit as the first layer of denial-of-service defence, but a server that does not set it explicitly accepts an unlimited number of simultaneous connections. Establishing the connections is sufficient; no valid request and no authentication are required.

The accept gate in httpdmanager:handlenewconnection/4 reads the option with httpdutil:lookup/2, which returns undefined when the key is absent, rather than the three-argument form carrying the 150 default that the neighbouring getustate/2 uses. Erlang term ordering places every integer before every atom, so the Count =< Max guard holds for any connection count and the server never returns {reject, busy}. Each accepted connection occupies a worker process and a socket for as long as it is held, driving the node towards process, memory and file descriptor exhaustion. Servers that set maxclients explicitly are unaffected, because a configured value is applied as intended.

This issue affects OTP from OTP 17.0 before OTP 27.3.4.17, from OTP 28.0 before OTP 28.5.0.6, and from OTP 29.0 before OTP 29.0.6, corresponding to inets from 5.10 before 9.3.2.7, from 9.4 before 9.6.2.3, and from 9.7 before 9.7.2.

Database specific
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/70xxx/CVE-2026-70399.json",
    "unresolved_ranges": [
        {
            "source": "AFFECTED_FIELD",
            "extracted_events": [
                {
                    "introduced": "17.0"
                },
                {
                    "fixed": "27.3.4.17"
                },
                {
                    "introduced": "28.0"
                },
                {
                    "fixed": "28.5.0.6"
                },
                {
                    "introduced": "29.0"
                },
                {
                    "fixed": "29.0.6"
                },
                {
                    "introduced": "5.10"
                },
                {
                    "fixed": "9.3.2.7"
                },
                {
                    "introduced": "9.4"
                },
                {
                    "fixed": "9.6.2.3"
                },
                {
                    "introduced": "9.7"
                },
                {
                    "fixed": "9.7.2"
                },
                {
                    "introduced": "d9674f32811cd5bb02b0d6656053b5ee226bc74c"
                },
                {
                    "fixed": "*"
                }
            ]
        },
        {
            "source": "CPE_FIELD",
            "extracted_events": [
                {
                    "introduced": "17.0"
                },
                {
                    "fixed": "27.3.4.17"
                },
                {
                    "introduced": "28.0"
                },
                {
                    "fixed": "28.5.0.6"
                },
                {
                    "introduced": "29.0"
                },
                {
                    "fixed": "29.0.6"
                }
            ]
        },
        {
            "source": "DESCRIPTION",
            "extracted_events": [
                {
                    "introduced": "17.0"
                },
                {
                    "introduced": "28.0"
                },
                {
                    "introduced": "29.0"
                },
                {
                    "introduced": "5.10"
                },
                {
                    "fixed": "9.3.2.7"
                },
                {
                    "introduced": "9.4"
                },
                {
                    "fixed": "9.6.2.3"
                },
                {
                    "introduced": "9.7"
                },
                {
                    "fixed": "9.7.2"
                }
            ]
        }
    ],
    "cna_assigner": "EEF",
    "cwe_ids": [
        "CWE-770"
    ]
}
References

Affected packages

Git / github.com/erlang/otp

Affected ranges

Type
GIT
Repo
https://github.com/erlang/otp
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
Fixed
Fixed
Database specific
Show details
{
    "source": "REFERENCES"
}

Affected versions

OTP-17.*
OTP-17.0
OTP-18.*
OTP-18.0
OTP-18.0-rc1
OTP-19.*
OTP-19.0
OTP-19.0-rc1
OTP-19.0-rc2
OTP-20.*
OTP-20.0
OTP-20.0-rc1
OTP-20.0-rc2
OTP-21.*
OTP-21.0
OTP-21.0-rc1
OTP-21.0-rc2
OTP-22.*
OTP-22.0
OTP-22.0-rc1
OTP-22.0-rc2
OTP-22.0-rc3
OTP-23.*
OTP-23.0
OTP-23.0-rc1
OTP-23.0-rc2
OTP-23.0-rc3
OTP-24.*
OTP-24.0
OTP-24.0-rc1
OTP-24.0-rc2
OTP-24.0-rc3
OTP-25.*
OTP-25.0
OTP-25.0-rc1
OTP-25.0-rc2
OTP-25.0-rc3
OTP-26.*
OTP-26.0
OTP-26.0-rc1
OTP-26.0-rc2
OTP-26.0-rc3
OTP-27.*
OTP-27.0
OTP-27.0-rc1
OTP-27.0-rc2
OTP-27.0-rc3
OTP-27.1
OTP-27.2
OTP-27.3
OTP-27.3.1
OTP-27.3.2
OTP-27.3.3
OTP-27.3.4
OTP-27.3.4.1
OTP-27.3.4.10
OTP-27.3.4.11
OTP-27.3.4.12
OTP-27.3.4.13
OTP-27.3.4.14
OTP-27.3.4.2
OTP-27.3.4.3
OTP-27.3.4.4
OTP-27.3.4.5
OTP-27.3.4.6
OTP-27.3.4.7
OTP-27.3.4.8
OTP-27.3.4.9
OTP-28.*
OTP-28.0
OTP-28.0-rc1
OTP-28.0-rc2
OTP-28.0-rc3
OTP-28.0-rc4
OTP-28.1
OTP-28.4
OTP-28.5
OTP-28.5.0.1
OTP-28.5.0.2
OTP-29.*
OTP-29.0
OTP-29.0-rc1
OTP-29.0-rc2
OTP-29.0-rc3
OTP-29.0.1
OTP-29.0.2
OTP_17.*
OTP_17.0-rc1
OTP_17.0-rc2
Other
OTP_R13B03
OTP_R13B04
OTP_R14A
OTP_R14B
OTP_R14B01
OTP_R14B02
OTP_R14B03
OTP_R15A
OTP_R15B
OTP_R16A_RELEASE_CANDIDATE
OTP_R16B
patch-base-27
patch-base-28

Database specific

source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-70399.json"