CVE-2026-99055tcp: reject net_iov in zerocopy receive mapping hints
- —Not scoredno CVSS score yet
- 0.17%Exploitation in 30 daysEPSS · top 94% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: tcp: reject net_iov in zerocopy receive mapping hints After copying a readable prefix, receive_fallback_to_copy() asks tcp_zerocopy_set_hint_for_skb() where page mapping can resume. If the next skb is unreadable, find_next_mappable_frag() passes its net_iov fragment to can_map_frag(). skb_frag_page() returns NULL for a net_iov, but can_map_frag() dereferences it in PageCompound(). A v7.2 KASAN run on a connected TCP socket with 64 readable bytes followed by a 4096-byte NET_IOV_DMABUF fragment reported: BUG: KASAN: null-ptr-deref in can_map_frag tcp_zerocopy_receive -> can_map_frag Kernel panic - not syncing: KASAN: panic_on_warn set The diagnostic inserted the net_iov directly because the test host has no devmem-capable NIC. Hardware end-to-end reachability remains untested and requires CONFIG_NET_DEVMEM plus a supported DMA-buf-bound RX queue. Reject all net_iov fragments before skb_frag_page(). This covers both DMABUF and IOURING net_iov types while leaving page-backed checks unchanged. With the guard, the same queue copied the readable prefix, returned a 4096-byte skip hint, and completed without a fault.
Timeline
ID reserved
By Linux
- 28 days later
· 28 days later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Received.
- EPSS (exploitation in 30 days)
- 0.17% · top 94% of all CVEs (13 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.
Affected products
- affected 9f6b619edf2e85746f261b42ae8f818a59d126f7 – < 563d3564513496b9ce3b3ba7a5154427554d0f06
- affected 9f6b619edf2e85746f261b42ae8f818a59d126f7 – < 1c7463ac0e99cc91c4eecc1b69a740ef1a619932
- affected 9f6b619edf2e85746f261b42ae8f818a59d126f7 – < 3aa6f536a95eb0617c313ae2eb76fdfa85331f85
- affected 9f6b619edf2e85746f261b42ae8f818a59d126f7 – < 8b1f0af1fd5fd113432233ed8a3862ee7c30a84f
- affected 6.12
- unaffected < 6.12
- unaffected 6.12.113 – ≤ 6.12.*
- unaffected 6.18.57 – ≤ 6.18.*
- unaffected 7.2.11 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References4
- https://git.kernel.org/stable/c/563d3564513496b9ce3b3ba7a5154427554d0f06 (opens in a new tab)
- https://git.kernel.org/stable/c/1c7463ac0e99cc91c4eecc1b69a740ef1a619932 (opens in a new tab)
- https://git.kernel.org/stable/c/3aa6f536a95eb0617c313ae2eb76fdfa85331f85 (opens in a new tab)
- https://git.kernel.org/stable/c/8b1f0af1fd5fd113432233ed8a3862ee7c30a84f (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-108850 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-99055)Record last updated .