CVE-2026-53218
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_exthdr: fix register tracking for F_PRESENT flag nft_exthdr_init() passes user-controlled priv->len to nft_parse_register_store(), which marks that many bytes in the register bitmap as initialized. However, when NFT_EXTHDR_F_PRESENT is set, the eval paths write only 1 byte (nft_reg_store8) or 4 bytes (*dest = 0 on TCP/DCCP error path). When len > 4, registers beyond the first are never written, retaining uninitialized stack data from nft_regs. Bail out if userspace requests too much data when F_PRESENT is set.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or โ if you've already worked around this in production โ publish your fix to the community-verified tier.
โ Propose a mitigation on Community โ Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
Debian Mixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Fixed | 6.12.94-1 |
| sid | Fixed | 7.0.13-1 |
| forky | Affected | โ |
| bullseye | Affected | โ |
| bookworm | Affected | โ |
References
- https://git.kernel.org/stable/c/8738b1b6d0e639ca1fc0f61516afd3557ac4ecc6
- https://git.kernel.org/stable/c/19748967d59c31d24d21d40b728570788310b237
- https://git.kernel.org/stable/c/46fc15a044e9938e7ea77786fb37edd2cd74f031
- https://git.kernel.org/stable/c/cd513e43b4b2bd1de39e2367bc4261c699a8652f
- https://git.kernel.org/stable/c/67b27434c43b68a97becda98c9f0c8cf6cba2134
- https://git.kernel.org/stable/c/78069a6d8bc86c9e036eb82c2af4a19cc1871a53
- https://git.kernel.org/stable/c/f08fb3d42fd3aad0b7a263da3ac3ebaf0845e265
- https://git.kernel.org/stable/c/772cecf198da732faebb5dcfc46d66a505be8495
- https://security-tracker.debian.org/tracker/CVE-2026-53218
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.