CVE-2026-52999
What it is
In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_osf: fix out-of-bounds read on option matching In nf_osf_match(), the nf_osf_hdr_ctx structure is initialized once and passed by reference to nf_osf_match_one() for each fingerprint checked. During TCP option parsing, nf_osf_match_one() advances the shared ctx->optp pointer. If a fingerprint perfectly matches, the function returns early without restoring ctx->optp to its initial state. If the user has configured NF_OSF_LOGLEVEL_ALL, the loop continues to the next fingerprint. However, because ctx->optp was not restored, the next call to nf_osf_match_one() starts parsing from the end of the options buffer. This causes subsequent matches to read garbage data and fail immediately, making it impossible to log more than one match or logging incorrect matches. Instead of using a shared ctx->optp pointer, pass the context as a constant pointer and use a local pointer (optp) for TCP option traversal. This makes nf_osf_match_one() strictly stateless from the caller's perspective, ensuring every fingerprint check starts at the correct option offset.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of data exposure, service disruption.
- Exploit odds
- 0.6% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.6% in the next 30 days (EPSS).
- Severity: 9.1 CRITICAL (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.6% · EPSS, next 30 days
- Weakness
- CWE-125 · Out-of-bounds read
- Record status
- Modified
Affected
- Linux Kernel < 4.20
- Linux Kernel < 5.0
- Linux Kernel < 5.10.258
- Linux Kernel < 5.15.209
- Linux Kernel < 6.1.175
- Linux Kernel < 6.6.141
- Linux Kernel < 6.12.91
- Linux Kernel < 6.18.33
Attack profile CVSS 3.1 · 9.1
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-52999.md and follow it. Check whether this project is affected by CVE-2026-52999. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/0145548346c4a30981a870a8ca00eac46ba27e85
- https://git.kernel.org/stable/c/1c136f2c44a5913646bac85303612fd0825197a0
- https://git.kernel.org/stable/c/1e19a07291bb8682c14c39a64725a3ae54ab8ccc
- https://git.kernel.org/stable/c/21883587593d7c8bb519a79460a0b5bc5ffbdabd
- https://git.kernel.org/stable/c/32e50f92c7cf3f4eba29622179a5fcdc2aebab41
- https://git.kernel.org/stable/c/70a3f31d25cf2ec9d4ddfa408120171ead955623
- https://git.kernel.org/stable/c/edb78a142d2e5948e63647c0646aa7e7886935f0
- https://git.kernel.org/stable/c/f5ca450087c3baf3651055e7a6de92600f827af3
References
- https://git.kernel.org/stable/c/0145548346c4a30981a870a8ca00eac46ba27e85
- https://git.kernel.org/stable/c/1c136f2c44a5913646bac85303612fd0825197a0
- https://git.kernel.org/stable/c/1e19a07291bb8682c14c39a64725a3ae54ab8ccc
- https://git.kernel.org/stable/c/21883587593d7c8bb519a79460a0b5bc5ffbdabd
- https://git.kernel.org/stable/c/32e50f92c7cf3f4eba29622179a5fcdc2aebab41
- https://git.kernel.org/stable/c/70a3f31d25cf2ec9d4ddfa408120171ead955623
- https://git.kernel.org/stable/c/edb78a142d2e5948e63647c0646aa7e7886935f0
- https://git.kernel.org/stable/c/f5ca450087c3baf3651055e7a6de92600f827af3
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html