Update idna from 3.11 to 3.15 (GHSA-65pc-fj4g-8rjx / CVE-2026-45409)

[Copilot]

idna==3.11 is vulnerable to a DoS via specially crafted inputs to idna.encode() that bypass the CVE-2024-3651 fix by invoking valid_contexto before length rejection. Fixed in 3.15.

Changes

• Pipfile — Added explicit idna = ">=3.15,<3.16" pin to enforce the patched version (previously an unpinned transitive dep of requests)
• Pipfile.lock — Updated idna from ==3.11 to ==3.15
• vendor/idna/ — Replaced vendored sources (were at 3.4) with 3.15

Reachability Assessment

Not reachable — high confidence.

The only requests usage is a POST to api.github.com — a static ASCII domain. idna.encode() is never called directly, and no user-supplied domain names flow into the HTTP client. This update satisfies vulnerability scanners; there is no active exposure.

Original prompt

---

This section details the Dependabot vulnerability alert you should resolve

<alert_title>Internationalized Domain Names in Applications (IDNA): Specially crafted inputs to idna.encode() can bypass CVE-2024-3651 fix</alert_title>
<alert_description>This is the same issue as CVE-2024-3651, however the original remediation in 2024 was not a complete fix. 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.

Impact

A specially crafted argument to the idna.encode() function could consume significant resources. This may lead to a denial-of-service.

Patches

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).

Workarounds

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.</alert_description>

moderate
GHSA-65pc-fj4g-8rjx, CVE-2026-45409
idna
pip
<vulnerable_versions>= 3.11</vulnerable_versions>
<patched_version>3.15</patched_version>
<manifest_path>Pipfile.lock</manifest_path>

https://github.com/kjd/idna/security/advisories/GHSA-65pc-fj4g-8rjx https://nvd.nist.gov/vuln/detail/CVE-2026-45409 https://github.com/advisories/GHSA-65pc-fj4g-8rjx

<task_instructions>Resolve this alert by updating the affected package to a non-vulnerable version. Prefer the lowest non-vulnerable version (see the patched_version field above) over the latest to minimize breaking changes. Include a Reachability Assessment section in the PR description. Review the alert_description field to understand which APIs, features, or configurations are affected, then search the codebase for usage of those specific items. If the vulnerable code path is reachable, explain how (which files, APIs, or call sites use the affected functionality) and note that the codebase is actively exposed to this vulnerability. If the vulnerable code path is not reachable, explain why (e.g. the affected API is never called, the vulnerable configuration is not used) and note that the update is primarily to satisfy vulnerability scanners rather than to address an active risk. If the advisory is too vague to determine reachability (e.g. 'improper input validation' with no specific API named), state that reachability could not be determined and explain why. Include a confidence level in the reachability assessment (e.g. high confidence if the advisory names a specific API and you confirmed it is or is not called, low confidence if the usage is indirect and hard to trace). If no patched version is available, check the alert_description field for a Workarounds section — the advisory may describe configuration changes or usage patterns that mitigate the vulnerability without a version update. If a workaround is available, apply it and leave a code comment referencing the advisory identifier explaining it is a temporary mitigation. If neither a patch nor a workaround is available, explain in the PR description why the alert cannot be resolved automatically so a human reviewer can take over. Inspect the repository to determine which package manager is used (e.g. lock files, config files, build scripts) and use that tooling to perform the update — do not edit lock files directly. If the version constraint in the manifest (e.g. package.json, Gemfile, pyproject.toml) caps the version below the fix, update the constraint first. For transitive dependencies, determine whether it is simpler to update the direct dependency that pulls in the vulnerable package or to update the transitive dependency directly, and choose the least disruptive approach. If upgrading to fix the vulnerability forces a major version bump or known breaking changes, review the changelog or release notes, then audit the codebase for usage of affected APIs and fix any breaking changes that are found. If the package manager fails to resolve dependencies (e.g. peer dependency conflicts, incompatible engine constraints), document the error in the PR description rather than attempting increasingly complex workarounds. After updating, check the lock file to confirm the package no longer resolves to a version in the vulnerable range. Keep changes minimal and tightly scoped. Ensure tests, build, type checking, and linting all pass after your changes. If there ...

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