CVE-2026-5773
Description
A flaw was found in libcurl. Due to a logical error in the connection reuse mechanism for SMB (Server Message Block) transfers, libcurl might reuse an existing SMB connection with a different share than intended. This vulnerability, categorized as CWE-488 (Exposure of Data Element to Wrong Session), could lead to the download of an incorrect file or the upload of a file to an unintended location when an application uses libcurl for SMB transfers.
Statement
This Moderate impact flaw in libcurl affects applications performing SMB transfers. A logical error in the SMB connection reuse mechanism can lead to unintended file downloads or uploads to incorrect locations. This impacts applications that rely on libcurl for secure and accurate SMB file operations.
Mitigation
To mitigate this issue, avoid using SMB for transfers with libcurl. As SMB support is opt-in since curl 8.20.0 and SMBv1 is deprecated, ensuring SMB functionality is disabled or not utilized in applications leveraging libcurl will prevent exposure. If SMB is required, consider upgrading to curl 8.20.0 or later, which addresses this flaw by preventing SMB connection reuse.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.5 | 7.5 | 7.5 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | Low | Low | Low |
| Privileges Required | None | None | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | Low | High | High |
| Integrity Impact | Low | None | None |
| Availability Impact | None | None | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Understanding the Weakness (CWE)
Other
Technical Impact: Varies by Context
This can lead to incorrect results and resultant weaknesses. For example, the code might inadvertently compare references to objects, instead of the relevant contents of those objects, causing two "equal" objects to be considered unequal.
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