Snowflake libsnowflakeclient: Stack-based Buffer Overflow
CVE-2026-16870 is a high-severity stack-based buffer overflow vulnerability in Snowflake libsnowflakeclient from Snowflake, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 2.9.2 as the first without the flaw, so updating Snowflake libsnowflakeclient to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.29% chance of exploitation within 30 days, higher than 71% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Snowflake libsnowflakeclient to 2.9.2 or a later version.
- Update Snowflake PHP PDO Driver to 4.1.0 or a later version.
- Update Snowflake ODBC Driver to 3.19.0 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Snowflake | Snowflake libsnowflakeclient | before 2.9.2 | 2.9.2 |
| Snowflake | Snowflake PHP PDO Driver | before 4.1.0 | 4.1.0 |
| Snowflake | Snowflake ODBC Driver | 2.16.3 up to, but not including, 3.19.0 | 3.19.0 |
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
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.
Official description
Multiple security vulnerabilities in Snowflake libsnowflakeclient versions prior to 2.9.2 could allow remote code execution and credential exfiltration. A stack-based buffer overflow in the file download path could allow remote code execution on a victim host. An attacker could exploit this by uploading a file with a crafted encryption metadata field to a shared internal stage that a victim process later downloads, and impact would be limited to deployments where principals with different privilege levels share the same internal stage. A related out-of-bounds write in the same download path could allow memory corruption with attacker-controlled write primitives. An attacker may exploit this through a crafted initialization vector metadata field on a shared stage, and impact would be limited by the same stage-write precondition. Improper validation of connection parameters could allow an attacker-controlled input to redirect outbound authentication requests — including credentials and tokens — to an attacker-controlled endpoint. Impact is limited to embedding deployments where a lower-privileged principal can influence connection configuration while higher-privileged service credentials are in use. The fix is available in Snowflake libsnowflakeclient version 2.9.2. The Snowflake PHP PDO Driver and Snowflake ODBC Driver embed the affected library; fixes are available in versions 4.1.0 and 3.19.0 respectively. Users must manually upgrade.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Stack-based Buffer Overflow
The product writes past the end of a buffer that was allocated on the stack.
How developers prevent this class of flaw
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
- Use an abstraction library to abstract away risky APIs. Not a complete solution.
- Implement and perform bounds checking on input.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other vulnerabilities in Snowflake libsnowflakeclient
- 8.2 High severity
Recent Stack-based Buffer Overflow vulnerabilities
- 8.8 High severity
- 7.2 High severity
- 8.8 High severity
- 9.8 Critical severity
- 7.3 High severity
- 7.8 High severity
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