# CVE-2025-43504 — Apple Xcode

> As of 2026-04-02, CVE-2025-43504 is a MEDIUM-severity vulnerability in Apple Xcode, CVSS v3.1 4.9, EPSS 0.3% (31.3th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2025-43504, most recently “CVE-2025-43504: Remote Pre-Authentication Buffer Overflow in LLDB debugserver (Xcode / iOS Developer Disk Image)”.

**Last updated:** 2026-04-02

## What is CVE-2025-43504?

A buffer overflow was addressed with improved bounds checking. This issue is fixed in Xcode 26.1. A user in a privileged network position may be able to cause a denial-of-service.

The record classifies CVE-2025-43504 under weakness class [CWE-119](https://intel.threadlinqs.com/cwe/CWE-119). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs high-privilege credentials, needs no user interaction, and has high impact on availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 366 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 4.9 — MEDIUM (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H`)
- **EPSS (FIRST):** 0.3% probability of exploitation in the next 30 days, higher than 31.3% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 5.7/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2025-11-04, last modified 2026-04-02

## Is CVE-2025-43504 being exploited?

Weaponised exploit code for CVE-2025-43504 is publicly available. 1 public proof-of-concept repository is tracked for this identifier. It currently carries a trending score of 21 in the Threadlinqs vulnerability feed.

- [calysteon/CVE-2025-43504](https://github.com/calysteon/CVE-2025-43504) (github)

## Affected products and versions

- [Apple](https://intel.threadlinqs.com/vendors/apple): Xcode

## How to fix CVE-2025-43504

Vendor advisory: [https://support.apple.com/en-us/125641](https://support.apple.com/en-us/125641). Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

## Threat activity tracking CVE-2025-43504

1 tracked threat in the Threadlinqs corpus references CVE-2025-43504, either in the campaign’s CVE list or as an indicator on the campaign record.

- [CVE-2025-43504: Remote Pre-Authentication Buffer Overflow in LLDB debugserver (Xcode / iOS Developer Disk Image)](https://intel.threadlinqs.com/threat/TL-2026-4906) — MEDIUM · 2026-10-31

## Sources

Enriched from CVE.org, NVD, FIRST EPSS, public proof-of-concept repositories. Last verified by Threadlinqs on 2026-11-02. This product uses the NVD API but is not endorsed or certified by the NVD.

**Other references**

- [support.apple.com](https://support.apple.com/en-us/125641)

Canonical: https://intel.threadlinqs.com/cve/CVE-2025-43504
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