CVE-2026-70399
published 2026-09-01CVE-2026-70399: Allocation of Resources Without Limits or Throttling vulnerability in Erlang/OTP inets httpd allows an unauthenticated remote attacker to cause denial of…
PriorityP356high8.7CVSS 4.0
AVNACLATNPRNUINVCNVINVAHSCNSINSANEXCRXIRXARXMAVXMACXMATXMPRXMUIXMVCXMVIXMVAXMSCXMSIXMSAXSXAUXRXVXREXUX
EPSS
0.93%
60.1th percentile
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.
Affected
8 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| erlang | otp | >= 17.0 < 27.3.4.17 | 27.3.4.17 |
| erlang | otp | >= 28.0 < 28.5.0.6 | 28.5.0.6 |
| erlang | otp | >= 29.0 < 29.0.6 | 29.0.6 |
| erlang | otp | >= 5.10 < 9.3.2.7 | 9.3.2.7 |
| erlang | otp | >= 9.4 < 9.6.2.3 | 9.6.2.3 |
| erlang | otp | >= 9.7 < 9.7.2 | 9.7.2 |
| erlang | otp | >= d9674f32811cd5bb02b0d6656053b5ee226bc74c < * | * |
| ubuntu | erlang | — | — |
CVSS provenance
nvdv4.08.7HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
vendor_redhat8.7HIGH
vendor_ubuntu7.5HIGH
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Ubuntu
Erlang vulnerabilities
vendor_ubuntu·2026-09-28·CVSS 7.5
CVE-2026-23941 [HIGH] Erlang vulnerabilities
Title: Erlang vulnerabilities
Summary: Several security issues were fixed in Erlang.
It was discovered that the Erlang Port Mapper Daemon did not properly
handle slow connections. A remote attacker could possibly use this issue
to cause a denial of service. (CVE-2026-42792)
It was discovered that Erlang incorrectly handled certain external term
format data, leading to heap corruption. An attacker could possibly use
this issue to cause Erlang to crash, resulting in a denial of service.
This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS.
(CVE-2026-55737)
It was discovered that Erlang incorrectly handled invalid external term
format data. An attacker could possibly use this issue to cause Erlang to
crash, resulting in a denial of service. This issue only affected Ubuntu
26.04
Red Hat
inets: inets: Denial of Service via unenforced connection limit
vendor_redhat·2026-09-01·CVSS 8.7
CVE-2026-70399 [HIGH] CWE-770 inets: inets: Denial of Service via unenforced connection limit
inets: inets: Denial of Service via unenforced connection limit
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
No detection rules found.
No public exploits indexed.
https://cna.erlef.org/cves/CVE-2026-70399.htmlhttps://github.com/erlang/otp/commit/6746dc4e1df5257ad8ac91cbbd167cb8b0274ce7https://github.com/erlang/otp/commit/d94a94c96eb4cccbd6f7d7da5975f0c035b69612https://github.com/erlang/otp/commit/e0050fc00c500a4fa9ba1f594603c787ff6d20b2https://github.com/erlang/otp/security/advisories/GHSA-pwvh-c689-f8q5https://osv.dev/vulnerability/EEF-CVE-2026-70399https://www.erlang.org/doc/system/versions.html#order-of-versions
2026-09-01
Published