---
id: CVE-2026-71562
title: >-
  Improper Validation of Specified Quantity in Input vulnerability in Erlang/OTP
  inets httpc allows a malicious or compromised HTTP server to degrade
  availability by returning a numeric header whose value is a very long run of
  digits.


  htt…
summary: >-
  Improper Validation of Specified Quantity in Input vulnerability in Erlang/OTP
  inets httpc allows a malicious or compromised HTTP server to degrade
  availability by returning a numeric header whose value is a very long run of
  digits.


  htt…
severity: medium
cvss: 6.3
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'
cwe:
  - CWE-1284
vendor: Erlang
product: otp
affected:
  - otp >= 17.0 < 27.3.4.17
  - otp >= 28.0 < 28.5.0.6
  - otp >= 29.0 < 29.0.6
  - inets >= 5.10 < 9.3.2.7
  - inets >= 9.4 < 9.6.2.3
  - inets >= 9.7 < 9.7.2
  - erlang/otp >= 84adefa331c4159d432d22840663c38f155cd4c1 < *
published: '2026-09-01'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T01:17:53.543'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-71562'
references:
  - url: 'https://cna.erlef.org/cves/CVE-2026-71562.html'
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/erlang/otp/commit/aba0fe8c2d700bf4ac94607cf7f00e53bbe4042d
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/erlang/otp/commit/e3be1cfe9f6cedd0cd20d9905e05601dfb31c8aa
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: 'https://github.com/erlang/otp/security/advisories/GHSA-cqx9-9hq6-m8wf'
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: 'https://osv.dev/vulnerability/EEF-CVE-2026-71562'
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: 'https://www.erlang.org/doc/system/versions.html#order-of-versions'
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-01T15:53:17.483996Z'
cvssSource: cna
epss: 0.00577
epssPercentile: 0.45199
ingestedAt: '2026-09-08T15:33:26.956Z'
---

## Overview

Improper Validation of Specified Quantity in Input vulnerability in Erlang/OTP inets httpc allows a malicious or compromised HTTP server to degrade availability by returning a numeric header whose value is a very long run of digits.

httpc_handler.erl converts the server-supplied Content-Length with list_to_integer/1 before comparing it against max_body_size, so the size check cannot protect the conversion, and the option defaults to nolimit in any case. The same unbounded conversion appears in httpc_response:format_response/1 for Content-Length and in httpc_response:get_ms_from_retry_after/1 for Retry-After, which is guarded only by a check that the first character is a digit. A value of up to roughly 1.26 million digits converts successfully and costs the requesting process hundreds of milliseconds of arbitrary-precision arithmetic per response. The conversion function is documented to accept integers of any size, so bounding the input is the caller's responsibility.

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. Whether OTP before OTP 17.0, corresponding to inets before 5.10, is affected is unknown.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.