8.7
HIGH CVSS 4.0
CVE-2026-69664
httpd parks a request worker indefinitely on a malformed chunk size sent after the headers
Description

Missing Release of Resource after Effective Lifetime vulnerability in Erlang/OTP inets httpd allows an unauthenticated remote attacker to cause denial of service by sending a request with a chunked body whose chunk-size line is not a hexadecimal number. The worker serving the connection is never released and no timeout reclaims it, so repeating the request across connections occupies every available worker and denies service to legitimate clients. No authentication is required and the default configuration is affected. The chunk-size line must arrive in a write separate from the headers. When the body accompanies the headers, httpd_request_handler:handle_body/3 calls http_chunk:decode/3 inside a try ... catch throw:Error, so the {error, {chunk_size, _}} thrown by http_chunk:decode_size/4 is answered with 400 Bad Request. When the chunk size arrives later, the decoder is resumed through a bare catch in httpd_request_handler:handle_info/2, which converts the throw into a return value rather than raising it; the resulting error tuple is then treated as the next decoder continuation, the socket is re-armed, and the worker waits for data that never comes. The request timeout has already been cancelled at the point the headers were accepted, and the periodic byte-rate check is only armed when minimum_bytes_per_second is configured, which it is not by default. This issue affects OTP from OTP 18.1.4 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 6.0.3 before 9.3.2.7, from 9.4 before 9.6.2.3, and from 9.7 before 9.7.2.

INFO

Published Date :

Sept. 1, 2026, 3:17 p.m.

Last Modified :

Sept. 1, 2026, 3:17 p.m.

Remotely Exploit :

Yes !

Source :

6b3ad84c-e1a6-4bf7-a703-f496b71e49db
Affected Products

The following products are affected by CVE-2026-69664 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Erlang otp
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 HIGH 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
CVSS 4.0 HIGH 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
Solution
Update Erlang/OTP inets to a patched version to prevent resource exhaustion.
  • Update Erlang/OTP to a fixed version.
  • Apply the latest inets security patches.
  • Review and configure request timeouts.
  • Monitor worker resource utilization.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-69664 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-69664 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-69664 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-69664 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by 6b3ad84c-e1a6-4bf7-a703-f496b71e49db

    Sep. 01, 2026

    Action Type Old Value New Value
    Added Description Missing Release of Resource after Effective Lifetime vulnerability in Erlang/OTP inets httpd allows an unauthenticated remote attacker to cause denial of service by sending a request with a chunked body whose chunk-size line is not a hexadecimal number. The worker serving the connection is never released and no timeout reclaims it, so repeating the request across connections occupies every available worker and denies service to legitimate clients. No authentication is required and the default configuration is affected. The chunk-size line must arrive in a write separate from the headers. When the body accompanies the headers, httpd_request_handler:handle_body/3 calls http_chunk:decode/3 inside a try ... catch throw:Error, so the {error, {chunk_size, _}} thrown by http_chunk:decode_size/4 is answered with 400 Bad Request. When the chunk size arrives later, the decoder is resumed through a bare catch in httpd_request_handler:handle_info/2, which converts the throw into a return value rather than raising it; the resulting error tuple is then treated as the next decoder continuation, the socket is re-armed, and the worker waits for data that never comes. The request timeout has already been cancelled at the point the headers were accepted, and the periodic byte-rate check is only armed when minimum_bytes_per_second is configured, which it is not by default. This issue affects OTP from OTP 18.1.4 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 6.0.3 before 9.3.2.7, from 9.4 before 9.6.2.3, and from 9.7 before 9.7.2.
    Added CVSS V4.0 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
    Added CWE CWE-772
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/69xxx/CVE-2026-69664.json">CVE-2026-69664</a>
    Added Reference https://cna.erlef.org/cves/CVE-2026-69664.html
    Added Reference https://github.com/erlang/otp/commit/a3adf63078438c86527d704e23282b7721d8ca12
    Added Reference https://github.com/erlang/otp/commit/bd4e74348c6be8a49f060da6fd48d43f3a960292
    Added Reference https://github.com/erlang/otp/commit/df1a9ca4666e2fdfc44886bfaae76de086d803f6
    Added Reference https://github.com/erlang/otp/security/advisories/GHSA-mr35-8h7w-w3gq
    Added Reference https://osv.dev/vulnerability/EEF-CVE-2026-69664
    Added Reference https://www.erlang.org/doc/system/versions.html#order-of-versions
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.