CVE-2025-12972 CVE-2025-12972
Attackers can write files outside the intended directory by crafting malicious tags when the File option is omitted in the out_file plugin.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-12972?
CVE-2025-12972 is a medium-severity path traversal vulnerability in FluentBit Fluent Bit, published on 24 Nov 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Fluent Bit out_file plugin does not properly sanitize tag values when deriving output file names. When the File option is omitted, the plugin uses untrusted tag input to construct file paths. This allows attackers with network access to craft tags containing path traversal sequences that cause Fluent Bit to write files outside the intended output directory.
Weakness: CWE-22
Which versions are affected by CVE-2025-12972?
1 open source package ship an affected version, including fluent-bit. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
fluent-bit Bitnami | From 4.1.0 | 4.1.1 |
Products include Treasuredata Fluent Bit.
How do I fix CVE-2025-12972?
Upgrade fluent-bit to 4.1.1 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2025-12972 being exploited?
There is no known exploitation of CVE-2025-12972 in the wild and no public exploit code.
Other vulnerabilities in FluentBit Fluent Bit
Sources
Also known as BIT-fluent-bit-2025-12972, GHSA-mjmc-4hm9-g39m.