# CVE-2026-121925: Buffer overflow in SAML authentication post-back URL handling in libsnowflakeclient and Snowflake PHP PDO Driver


- **Severity:** Medium 6.6 (`CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 4 Nov 2026
- **Updated:** 4 Nov 2026
- **Also known as:** GHSA-cmv8-j38c-qhxx

## What is CVE-2026-121925?

CVE-2026-121925 is a medium-severity vulnerability in Snowflake Libsnowflakeclient, published on 4 Nov 2026. 

### Official description

A stack-based buffer overflow in libsnowflakeclient and the Snowflake PHP PDO Driver could, under specific conditions, result in memory corruption during SAML-based authentication. During a native SSO/SAML login flow, the affected drivers may have copied a value taken from the identity provider's HTML response into a fixed-size memory buffer without first validating the length of that value. An attacker who controlled or had compromised the configured identity provider — or who was able to redirect the SAML single sign-on endpoint to an attacker-controlled server — might have leveraged this by returning an oversized response, potentially resulting in a crash or, in specific circumstances, remote code execution within the context of the application running the library. The fix is available in libsnowflakeclient version 2.11.1 and Snowflake PHP PDO Driver version 4.3.0. Users must manually upgrade.

Weakness: CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2026-121925?


## How do I fix CVE-2026-121925?

No fix has been published for CVE-2026-121925 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-121925 being exploited?

There is no known exploitation of CVE-2026-121925 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-121925 and fix it if it is affected.

What it is: CVE-2026-121925 is a medium-severity vulnerability in Snowflake Libsnowflakeclient, published on 4 Nov 2026. 
Exploitation: There is no known exploitation of CVE-2026-121925 in the wild and no public exploit code.

Affected product: Snowflake Libsnowflakeclient. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-121925/ (Markdown: https://insights.sbomify.com/CVE-2026-121925/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-121925
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-121925
- OSV: https://osv.dev/vulnerability/CVE-2026-121925

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-121925/
Summaries are generated and may contain mistakes; the official description above is the record.