---
schema_version: '1.0'
id: security-20260711-3d84c1
url: https://osv.dev/vulnerability/PYSEC-2026-215
url_hash: 3d84c168cd7f4b28509e878ba842f3623fa527d9b1fb3f20e28cd2569c415c66
canonical_url: https://osv.dev/vulnerability/PYSEC-2026-215
source: osv:pypa
category: security/library
category_raw: cve/library
region: null
tags:
- cve
- CVE-2026-45409
- PYSEC-2026-215
- severity:CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- idna
- PyPI
lang: en
published_at: '2026-06-05T23:16:43Z'
fetched_at: '2026-07-11T06:37:17Z'
updated_at: '2026-07-11T06:39:11Z'
status: published
content_hash: 84fbc4a973266f4737a2afc6d4469ec8dfc4c52d0a70b3a90ae855c367b3964f
license_note: full
summary: Internationalized Domain Names in Applications (IDNA) for Python provides
  support for Internationalized Domain Names in Applications (IDNA) and Unicode IDNA
  Compatibility Processing. In versions prior to 3.15, payloads such as `"\u0660"
  * N` or `"\u30fb" * N + "\u6f22"` utilize t
summary_source: rss
summary_en: Internationalized Domain Names in Applications (IDNA) for Python provides
  support for Internationalized Domain Names in Applications (IDNA) and Unicode IDNA
  Compatibility Processing. In versions prior to 3.15, payloads such as `"\u0660"
  * N` or `"\u30fb" * N + "\u6f22"` utilize t
entities: []
key_facts: []
related: []
related_auto: []
title: CVE-2026-45409 — idna
---

# CVE-2026-45409 — idna

## TL;DR
Internationalized Domain Names in Applications (IDNA) for Python provides support for Internationalized Domain Names in Applications (IDNA) and Unicode IDNA Compatibility Processing. In versions prior to 3.15, payloads such as `"\u0660" * N` or `"\u30fb" * N + "\u6f22"` utilize t

## Key Points
- cve / CVE-2026-45409 / PYSEC-2026-215 / severity:CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L / idna / PyPI

## Details
**Severity:** CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
**Advisory:** PYSEC-2026-215 (CVE-2026-45409)

**Affected (your watchlist):**
- `PyPI:idna` 3.11 → fixed in 3.15 [docker/docker-llmwiki+docker/docker-mcp]
- `PyPI:idna` 3.13 → fixed in 3.15 [docker/local]

**Details:**
Internationalized Domain Names in Applications (IDNA) for Python provides support for Internationalized Domain Names in Applications (IDNA) and Unicode IDNA Compatibility Processing. In versions prior to 3.15, payloads such as `"\u0660" * N` or `"\u30fb" * N + "\u6f22"` utilize the `valid_contexto` function prior to length rejection, and for high values of `N` will take a long time to process. This is the same issue as CVE-2024-3651, however the original remediation in 2024 was not a complete fix. A specially crafted argument to the `idna.encode()` function could consume significant resources. This may lead to a denial-of-service. Starting in version 3.14, the function rejects long inputs as soon as practicable prior to any further processing to minimize resource consumption. In version 3.15, this approach was extended to lesser used alternate functions (i.e. per-label conversions and codec support). A workaround is available. Domain names cannot exceed 253 characters in length. If this length limit is enforced prior to passing the domain to the `idna.encode()` function, it should no longer consume significant resources. This is triggered by arbitrarily large inputs that would not occur in normal usage, but may be passed to the library assuming there is no preliminary input validation by the higher-level application.

**References:**
- https://github.com/kjd/idna/security/advisories/GHSA-65pc-fj4g-8rjx

_Data: OSV.dev (upstream: pypa) — https://osv.dev/vulnerability/PYSEC-2026-215_

## Source
元記事: [CVE-2026-45409 — idna](https://osv.dev/vulnerability/PYSEC-2026-215) — published 2026-06-05T23:16:43Z