🛡️ CVE-2025-39689 on Debian — linux
Description
In the Linux kernel, the following vulnerability has been resolved: ftrace: Also allocate and copy hash for reading of filter files Currently the reader of set_ftrace_filter and set_ftrace_notrace just adds the pointer to the global tracer hash to its iterator. Unlike the writer that allocates a copy of the hash, the reader keeps the pointer to the filter hashes. This is problematic because this pointer is static across function calls that release the locks that can update the global tracer hashes. This can cause UAF and similar bugs. Allocate and copy the hash for reading the filter files like it is done for the writers. This not only fixes UAF bugs, but also makes the code a bit simpler as it doesn't have to differentiate when to free the iterator's hash between writers and readers.
Distribution advisory
This page covers CVE-2025-39689 as tracked by Debian, for the package linux. The fix is available in version 6.16.5-1; earlier versions remain affected.
How this vulnerability can be exploited
This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.
Weakness class
DEBIAN-CVE-2025-39689 is classified as CWE-416: Use After Free. Memory is used after being released, so its contents may already belong to something else.
Affected software
DEBIAN-CVE-2025-39689 is recorded against 2 packages.
- linux (fixed in 6.16.5-1)
- linux-6.1 (fixed in 6.1.153-1~deb11u1)
Timeline and source
Published on 5 September 2025 and last revised on 4 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.
References
CVE-2025-39689 on other distributions
Each distribution ships its own build and its own fixed version. Pick the one you run:
Details
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| linux | — | 6.16.5-1 |
| linux-6.1 | — | 6.1.153-1~deb11u1 |
References
Similar Threats
- Unknown CGA-23jx-hhcx-m389
- Unknown CGA-2qp7-6757-fmgc
- Unknown CGA-2rj5-jc55-r267
- Unknown CGA-3m96-cwq8-6xmx
- Unknown CGA-3qj9-973w-fh9g
Site Security Check
Is linux part of your stack?
DEBIAN-CVE-2025-39689 is rated CVSS 7.8 High. BotEraser scans your installation against known CVE records and tells you whether this vulnerability applies to the versions you actually run.
Scan My Site Free →No credit card required · Results in minutes
ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.