Out-of-bounds Read Affecting curl package, versions [7.31.0,8.16.0)
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-UNMANAGED-CURL-12632967
- published12 Sept 2025
- disclosed12 Sept 2025
- creditBig Sleep
Introduced: 12 Sep 2025
CVE-2025-9086 (opens in a new tab)How to fix?
Upgrade curl to version 8.16.0 or higher.
Overview
curl is a command line tool and library for transferring data with URL syntax, supporting DICT, FILE, FTP, FTPS, GOPHER, GOPHERS, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, MQTT, POP3, POP3S, RTMP, RTMPS, RTSP, SCP, SFTP, SMB, SMBS, SMTP, SMTPS, TELNET and TFTP. libcurl offers a myriad of powerful features.
Affected versions of this package are vulnerable to Out-of-bounds Read due to improper validation in the path comparison process. An attacker can cause a crash or override the contents of a secure cookie by setting a cookie with the secure keyword for an HTTPS site, then redirecting to the same hostname over HTTP and setting a cookie with the same name but a different path. This may result in reading outside a heap buffer boundary, potentially exposing or corrupting sensitive data.
Notes:
This is only exploitable if the attacker is in control of the
http://site that uses the same name as thehttps://version, or otherwise possesses MITM capability.The attacker has no way to control or guess what is in the heap memory following the path buffer that is being read out of bounds, making it a fragile operation.
This flaw does not affect the curl command line tool. While the curl tool can be tricked to override the cookie in the same way, that does not make it a vulnerability for the tool.