CVE-2026-70399
Description
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
References
- https://cna.erlef.org/cves/CVE-2026-70399.html
- https://github.com/erlang/otp/commit/6746dc4e1df5257ad8ac91cbbd167cb8b0274ce7
- https://github.com/erlang/otp/commit/d94a94c96eb4cccbd6f7d7da5975f0c035b69612
- https://github.com/erlang/otp/commit/e0050fc00c500a4fa9ba1f594603c787ff6d20b2
- https://github.com/erlang/otp/security/advisories/GHSA-pwvh-c689-f8q5
- https://osv.dev/vulnerability/EEF-CVE-2026-70399
- https://www.erlang.org/doc/system/versions.html#order-of-versions
CWEs
CWE-770
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.