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
2026-09-01T14:33:05Z
Modified
2026-09-09T03:31:02Z
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 httpd_manager:handle_new_connection/4 reads the option with httpd_util:lookup/2, which returns undefined when the key is absent, rather than the three-argument form carrying the 150 default that the neighbouring get_ustate/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 max_clients 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
{
    "cna_assigner":  "EEF",
    "cwe_ids":  [
        "CWE-770"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/70xxx/CVE-2026-70399.json",
    "unresolved_ranges":  [
        {
            "extracted_events":  [
                {
                    "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":  "AFFECTED_FIELD"
        }
    ]
}
References

Affected packages

Git / github.com/erlang/otp

Affected ranges

Type
GIT
Repo
https://github.com/erlang/otp
Events
Database specific
Show details
{
    "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":  [
        "AFFECTED_FIELD",
        "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-27.3.4.15
OTP-27.3.4.16
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-28.1
OTP-28.4
OTP-28.5
OTP-28.5.0.1
OTP-28.5.0.2
OTP-28.5.0.3
OTP-28.5.0.4
OTP-28.5.0.5
OTP-29.*
OTP-29.0
OTP-29.0.1
OTP-29.0.2
OTP-29.0.3
OTP-29.0.4
OTP-29.0.5
Other
patch-base-27
patch-base-28

Database specific

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