curl: Exposure of Data Element to Wrong Session
CVE-2026-80231 is a high-severity exposure of data element to wrong session vulnerability in curl, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 8.14.2, 8.16.1, 8.20.1 as the first without the flaw, so updating curl to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.9% chance of exploitation within 30 days, higher than 60% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update curl to 8.14.2 or 8.16.1 or 8.20.1 or 8.22.0, whichever matches your release line, or a later version.
- Read the advisory on curl.se for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Curl | curl | 7.71.0 up to, but not including, 8.14.2; 8.15.0 up to, but not including, 8.16.1; 8.17.0 up to, but not including, 8.20.1; 8.21.0 up to, but not including, 8.22.0; 148534db57dda611cf8516e92e4d6e35fc1e5074 up to, but not including, 7be1e70cb6bcd83e130ecfe8cb91b6a7dcdeff42; 8.21.0; 8.20.0; 8.19.0; and 32 more ranges | 8.14.2, 8.16.1, 8.20.1, 8.22.0, 7be1e70cb6bcd83e130ecfe8cb91b6a7dcdeff42 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CISA (ADP).
Official description
A flaw in libcurl makes it wrongly reuse an existing HTTPS connection setup for a given hostname even when using a different Native CA Store setting (`CURLSSLOPT_NATIVE_CA`) than when the connection was created.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Exposure of Data Element to Wrong Session
The product does not sufficiently enforce boundaries between the states of different sessions, causing data to be provided to, or used by, the wrong session.
How developers prevent this class of flaw
- Protect the application's sessions from information leakage. Make sure that a session's data is not used or visible by other sessions.
- Use a static analysis tool to scan the code for information leakage vulnerabilities (e.g. Singleton Member Field).
- In a multithreading environment, storing user data in Servlet member fields introduces a data access race condition. Do not use member fields to store information in the Servlet.
More Exposure of Data Element to Wrong Session vulnerabilities (CWE-488)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Patches and release notes
- hackerone.com/reports/3969368Exploit, Mitigation, Third Party Advisory
Other vulnerabilities in curl
- 7.5 High severity
- 9.1 Critical severity
- 7.5 High severity
- 7.5 High severity
- 8.1 High severity
- 9.1 Critical severity
Recent Exposure of Data Element to Wrong Session vulnerabilities
- 9.8 Critical severity
- 7.4 High severity
- 10.0 Critical severity
- 10.0 Critical severity
- 7.7 High severity
- 7.5 High severity
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