CVE-2026-43500
Description
In the Linux kernel, the following vulnerability has been resolved: rxrpc: Also unshare DATA/RESPONSE packets when paged frags are present The DATA-packet handler in rxrpc_input_call_event() and the RESPONSE handler in rxrpc_verify_response() copy the skb to a linear one before calling into the security ops only when skb_cloned() is true. An skb that is not cloned but still carries externally-owned paged fragments (e.g. SKBFL_SHARED_FRAG set by splice() into a UDP socket via __ip_append_data, or a chained skb_has_frag_list()) falls through to the in-place decryption path, which binds the frag pages directly into the AEAD/skcipher SGL via skb_to_sgvec(). Extend the gate to also unshare when skb_has_frag_list() or skb_has_shared_frag() is true. This catches the splice-loopback vector and other externally-shared frag sources while preserving the zero-copy fast path for skbs whose frags are kernel-private (e.g. NIC page_pool RX, GRO). The OOM/trace handling already in place is reused.
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 — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
Exploits
Public proof-of-concept code below. AS-IS, for defenders and authorised testing only.
Metasploit modules
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | fixed | 6.1.170-3 |
| debian | bullseye | fixed | 5.10.251-4 |
| debian | forky | fixed | 7.0.4-1 |
| debian | sid | fixed | 7.0.4-1 |
| debian | trixie | fixed | 6.12.86-1 |
| linux-kernel | affected | 6.18.29 | |
| linux-kernel | 5.3 | affected | |
| linux-kernel | 7.1 | affected | |
| windows | affected | |
References
- https://git.kernel.org/stable/c/3711382a77342a9a1c3d2e7330dcfc7ea927f568
- https://git.kernel.org/stable/c/3eae0f4f9f7206a4801efa5e0235c25bbd5a412c
- https://git.kernel.org/stable/c/7c504ffab3efce8f7e4f463b314ae31030bdf18b
- https://git.kernel.org/stable/c/aa54b1d27fe0c2b78e664a34fd0fdf7cd1960d71
- https://git.kernel.org/stable/c/d45179f8795222ce858770dc619abe51f9d24411
- https://github.com/V4bel/dirtyfrag
- https://www.suse.com/security/cve/CVE-2026-43500.html
- https://security-tracker.debian.org/tracker/CVE-2026-43500
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-43500
CWEs
CWE-787
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.