CVE-2026-45409VulnerabilityPublished 13 Aug 2026Updated 9 Nov 2026

Icloudpd: Internationalized Domain Names

Affects icloudpdSource GCVE Database

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Mentioned vulnerabilities

CVE-2024-3651

Authoritative record:CVE-2026-45409· Medium 6.9

Not known to be exploited · CVSS 6.9 Medium : upgrade to 1.33.0 when convenient.

Data as of 9 Nov 2026, 19:47 UTC

CVSS 4.0 base score

6.9Medium

How severe the flaw is on the 0–10 CVSS scale.

Patch: Available – fixed in 1.33.0

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: None
Vulnerable system availability: Low
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the Vulnerable System are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 5 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 9 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade icloudpd to 1.33.0.

Affected software

Product	Affected	Fixed in
Homebrewicloudpd`pkg:brew/icloudpd`Other threats	Affected >=1.17.3 <1.33.0	Fixed in 1.33.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade icloudpd to version 1.33.0 or later, where the vulnerability is fixed by early rejection of long inputs. Alternatively, enforce domain name length limits (maximum 253 characters) before passing inputs to idna.encode() to prevent excessive resource consumption. No other mitigation is required as the patch fully addresses the issue.

Description

A vulnerability in icloudpd's use of the idna.encode() function allows specially crafted inputs to cause excessive resource consumption, leading to denial-of-service. This issue is a follow-up to CVE-2024-3651, where the initial fix was incomplete. Versions from 1.17.3 up to but not including 1.33.0 are affected. The vulnerability is mitigated in version 1.33.0 by rejecting long inputs early to prevent resource exhaustion. Enforcing the domain name length limit of 253 characters before calling idna.encode() also mitigates the issue.

Impact

An attacker can supply specially crafted domain name inputs to the idna.encode() function causing it to consume excessive CPU resources, potentially resulting in denial-of-service. There is no impact on confidentiality or integrity. The impact is limited to availability degradation due to resource exhaustion.

Summary

The vulnerability in icloudpd involves the idna.encode() function processing specially crafted inputs that exploit the valid_contexto function, causing prolonged processing times and significant resource consumption. This can lead to denial-of-service conditions. The original fix for CVE-2024-3651 was incomplete, allowing payloads with repeated Unicode characters to bypass length checks. Starting with icloudpd version 3.14, long inputs are rejected as early as possible to minimize resource use, and version 3.15 extended this to additional functions. The vulnerability affects versions >=1.17.3 and <1.33.0, with the fix implemented in 1.33.0.

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Affected software

Description

AI analysisMachine-generated, updated 9 Nov 2026, 19:47 UTC

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