Haxx Curl
CVE-2025-10148
curl's WebSocket code did not update the 32-bit mask pattern for each new outgoing frame as the specification says. Instead it used a fixed mask that persisted and was used throughout the entire connection. A predictable mask pattern allows for a malicious server to induce traffic between the two communicating parties that could be interpreted by an involved proxy (configured or transparent) as genuine, real, HTTP traffic with content and thereby poison its cache. That cached poisoned content could then be served to all users of that proxy.
What this means for your business
- It affects Haxx Curl. It matters if your company, or a supplier that handles your data, runs it.
- An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
What to do
- 1Check whether your company or your suppliers run Haxx Curl, and which version. The affected versions are listed further down this page.
- 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.
Not sure if your company is exposed?
Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.
Scoring
- CVSS
- 5.3 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N- Weakness
- CWE-340
- Assigned by
- 2499f714-1537-4658-8207-48ae4bb9eae9
Dates
- Published
- 2025-09-12
- Last modified
- 2026-09-15
- Sources
- NVD
Affected products
- Haxx Curl8.11.0 - 8.16.0
As listed in the NVD configuration data. Not a statement about your estate.