Snowflake Connector for Python: Improper Validation of Certificate with Host Mismatch
CVE-2026-15925 is a critical-severity improper validation of certificate with host mismatch vulnerability in Snowflake Connector for Python from Snowflake, with a CVSS 4.0 base score of 9.2 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 3.18.1, 4.7.1 as the first without the flaw, so updating Snowflake Connector for Python to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.18% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Snowflake Connector for Python to 3.18.1 or 4.7.1, whichever matches your release line, or a later version.
- 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 |
|---|---|---|---|
| Snowflake | Snowflake Connector for Python | 3.17.4 up to, but not including, 3.18.1; 4.0.0 up to, but not including, 4.7.1 | 3.18.1, 4.7.1 |
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.
- Attack requirements
- PresentThe target must be in a specific state or configuration for the attack to work.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Confidentiality (vulnerable system)
- HighSerious loss of confidentiality on the vulnerable system.
- Integrity (vulnerable system)
- HighSerious loss of integrity on the vulnerable system.
- Availability (vulnerable system)
- LowLimited loss of availability on the vulnerable system.
- Confidentiality (other systems)
- NoneNo loss of confidentiality on systems beyond the vulnerable one.
- Integrity (other systems)
- NoneNo loss of integrity on systems beyond the vulnerable one.
- Availability (other systems)
- NoneNo loss of availability on systems beyond the vulnerable one.
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA.
Official description
Improper TLS hostname verification in Snowflake Connector for Python versions prior to 4.7.1 and 3.18.1 may have allowed a network-positioned attacker to bypass certificate hostname validation on HTTPS connections made by the connector. An attacker with on-path network access could exploit this by intercepting or redirecting network traffic and presenting a certificate signed by any trusted CA for any domain, causing the connector to accept connections without validating that the certificate matched the requested hostname. Successful exploitation requires an on-path traffic interception capability (e.g. ARP/DNS poisoning, rogue access point, BGP hijacking, or malicious proxy/exit node). This vulnerability may have exposed credentials, query data, and staged file contents to interception and tampering, and may have enabled the attacker to issue arbitrary SQL within the context of the victim's connector session. Impact is limited by the privileges of the affected Snowflake role. The fix is available in Snowflake Connector for Python versions 4.7.1 and 3.18.1. Users must manually upgrade.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Validation of Certificate with Host Mismatch
The product communicates with a host that provides a certificate, but the product does not properly ensure that the certificate is actually associated with that host.
How developers prevent this class of flaw
- In order to ensure data integrity, the certificate must be valid, and it must pertain to the site that is being accessed.Fully check the hostname of the certificate and provide the user with adequate information about the nature of the problem and how to proceed.
- If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.
- Be careful of other weaknesses in the code that checks the hostname, since it is still possible to incorrectly check the hostname. For example, attackers could create a certificate with a name that begins with a trusted name followed by a NUL byte, which could cause some string-based comparisons to only examine the portion that contains the trusted name.
More Improper Validation of Certificate with Host Mismatch vulnerabilities (CWE-297)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other vulnerabilities in Snowflake Connector for Python
- 8.1 High severity
- 8.2 High severity
- 7.4 High severity
Recent Improper Validation of Certificate with Host Mismatch vulnerabilities
- 7.4 High severity
- 7.5 High severity
- 7.4 High severity
- 8.5 High severity
- 7.3 High severity
- 8.1 High severity
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