CVE-2025-10148

Published Sep 12, 2025

Last updated 3 months ago

CVSS medium 5.3

Overview

Description
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.
Source
2499f714-1537-4658-8207-48ae4bb9eae9
NVD status
Analyzed
Products
curl

Risk scores

CVSS 3.1

Type
Secondary
Base score
5.3
Impact score
1.4
Exploitability score
3.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Severity
MEDIUM

Weaknesses

nvd@nist.gov
NVD-CWE-noinfo

Social media

Hype score
Not currently trending

  1. 🚨 CRITICAL: #Fedora 42 users must patch #curl now! CVE-2025-9086: Out-of-bounds read vuln (cookie path) CVE-2025-10148: Predictable WebSocket mask Risks: DoS, info disclosure, MiTM attacks. Read more: 👉 https://t.co/CLbfkTYifp #Security https://t.co/cqMgLtbGaD

    @Cezar_H_Linux

    21 Sept 2025

    55 Impressions

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  2. 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 w… https://t.co/xDXY21NXyw

    @CVEnew

    12 Sept 2025

    419 Impressions

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  3. curlでSeverity: Lowの脆弱性2件 CVE-2025-10148 predictable WebSocket mask https://t.co/HhmfZBZS2a CVE-2025-9086 Out of bounds read for cookie path https://t.co/cFIv6r9MgP

    @autumn_good_35

    10 Sept 2025

    53 Impressions

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Configurations

Related CVEs

  1. curl would wrongly reuse an existing HTTP proxy connection doing CONNECT to a server, even if the new request uses different credentials for the HTTP proxy. The proper behavior is to create or use a separate connection.•CVE-2026-3784
  2. When an OAuth2 bearer token is used for an HTTP(S) transfer, and that transfer performs a redirect to a second URL, curl could leak that token to the second hostname under some circumstances. If the hostname that the first request is redirected to has information in the used .netrc file, with either of the `machine` or `default` keywords, curl would pass on the bearer token set for the first host also to the second one.•CVE-2026-3783
  3. When doing a second SMB request to the same host again, curl would wrongly use a data pointer pointing into already freed memory.•CVE-2026-3805
  4. libcurl can in some circumstances reuse the wrong connection when asked to do an Negotiate-authenticated HTTP or HTTPS request. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of criterion must first be met. Due to a logical error in the code, a request that was issued by an application could wrongfully reuse an existing connection to the same server that was authenticated using different credentials. One underlying reason being that Negotiate sometimes authenticates *connections* and not *requests*, contrary to how HTTP is designed to work. An application that allows Negotiate authentication to a server (that responds wanting Negotiate) with `user1:password1` and then does another operation to the same server also using Negotiate but with `user2:password2` (while the previous connection is still alive) - the second request wrongly reused the same connection and since it then sees that the Negotiate negotiation is already made, it just sends the request over that connection thinking it uses the user2 credentials when it is in fact still using the connection authenticated for user1... The set of authentication methods to use is set with `CURLOPT_HTTPAUTH`. Applications can disable libcurl's reuse of connections and thus mitigate this problem, by using one of the following libcurl options to alter how connections are or are not reused: `CURLOPT_FRESH_CONNECT`, `CURLOPT_MAXCONNECTS` and `CURLMOPT_MAX_HOST_CONNECTIONS` (if using the curl_multi API).•CVE-2026-1965
  5. When doing SSH-based transfers using either SCP or SFTP, and asked to do public key authentication, curl would wrongly still ask and authenticate using a locally running SSH agent.•CVE-2025-15224

References

Sources include official advisories and independent security research.