filelock: Symlink swap during SoftFileLock's writability check leaks whether a path exists and is writable by the lock taker
filelock is a platform-independent file lock for Python. From 3.32.6 until 4.2.1, SoftFileLock can follow a swapped symbolic link during the conditional os.access writability check for a node without its owner-write bit, allowing another local user on a platform and directory configuration that follows the link to infer whether a chosen path exists and is writable from the observable acquisition result. This issue is fixed in version 4.2.1.
CVE-2026-112912
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-112912
filelock
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "tox-dev",
"product": "filelock",
"versions": [
{
"status": "affected",
"version": ">= 3.32.6, < 4.2.1"
}
]
}
]- Related CVEs
- CVE-2026-112912
Source reference:
/cveMetadata/cveId
Publisher severity
low
Source reference: /containers/cna/metrics
- Event
- #42279 · Revision 1
- Added to Heist Feed
- Publisher date