Quick answers
- Is CVE-2026-99284 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-99284 being exploited in the wild.
- How severe is CVE-2026-99284?
- Informational severity, published 7 November 2026.
- Which products and versions are affected?
- Linux Kernel Multiple versions through at least 6.x.
- Is there a fix for CVE-2026-99284?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-99284 attacked?
- It is attacked over the network or with local access, in an operating system.
- Am I affected by CVE-2026-99284?
- Check whether you run Linux Kernel at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The skb_zerocopy() function in net/core/skbuff.c copies fragment descriptors between packet buffers but fails to propagate the SKBFL_SHARED_FRAG flag, breaking the skb_has_shared_frag() check that ESP input handlers rely on to prevent in-place decryption on shared fragments. An unprivileged attacker can create packets through nfnetlink_queue or OpenVSwitch upcalls that bypass skb_cow_data() checks, leading to direct writes into kernel page-cache backing root-owned files. The fix adds a single flag propagation line during fragment transfer.
Affected products
- Linux Linux Kernel Multiple versions through at least 6.x
Timeline
- 2026-11-07: disclosed