CVE-2026-46323
In the Linux kernel, the following vulnerability has been resolved: net: gro: don't merge zcopy skbs skb_gro_receive() can currently copy frags between the source and GRO skb, without checking the zerocopy status, and in particular the SKBFL_MANAGED_FRAG_REFS flag. When SKBFL_MANAGED_FRAG_REFS is set, the skb doesn't hold a reference on the pages in shinfo->frags. Appending those frags to another skb's frags without fixing up the page refcount can lead to UAF. When either the last skb in the GRO chain (the one we would append frags to) or the source skb is zerocopy, don't merge the skbs.
Executive briefing
The source record describes: In the Linux kernel, the following vulnerability has been resolved: net: gro: don't merge zcopy skbs skb_gro_receive() can currently copy frags between the source and GRO skb, without checking the zerocopy status, and in particular the SKBFL_MANAGED_FRAG_REFS flag. When SKBFL_MANAGED_FRAG_REFS is set, the skb doesn't hold a reference on the pages in shinfo->frags. Appending those frags to another skb's frags without fixing up the page refcount can lead to UAF. When either the last skb in the GRO chain (the one we would append frags to) or the source skb is zerocopy, don't merge the skbs. The practical risk depends on whether an affected product/version is present, reachable and configured in an exploitable way. Review the affected-product evidence and linked vendor advisories before assigning exposure status.
Evidence confidence: Moderate Evidence-derived, not an exploitability verdict
Severity & attack characteristics
CVSS vector:CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Technical explanation & impact
The technical mechanism is not expanded beyond the source description unless a referenced advisory supplies additional evidence. Read the linked vendor/CERT advisories for root-cause detail.
Potential impact must be interpreted from the published CVSS impact metrics and the affected component. A CVSS impact score is not proof that a particular asset is exploitable.
Weakness classification
CWE-416CWE-123Affected products and versions
Products below are parsed from NVD vulnerable CPE configuration entries. Version boundaries are shown as published; verify applicability with the vendor.
| Vendor | Product | Version evidence |
|---|---|---|
| linux | linux_kernel | from (inclusive) 6.19; before 7.0.11 · CPE version 7.1 · CPE version 7.1 · CPE version 7.1 · CPE version 7.1 |
Remediation & validation
- Identify exposure by comparing the affected product and version ranges with your asset inventory, SBOM and externally exposed services.
- Review the linked vendor security advisory or patch notes. Upgrade to a vendor-confirmed fixed release; do not infer a fixed version from the CVE description.
- Until patched, consider restricting network access or disabling the affected feature where operationally safe. These are temporary controls, not a substitute for a vendor fix.
- Validate the remediation with a version check and vulnerability rescan, then retain change evidence.
No fixed version is displayed unless it is explicitly established by a vendor advisory. Follow the vendor's release notes for exact product and branch applicability.
Vendor advisories, patches & exploit references
- https://git.kernel.org/stable/c/1f9c828556416fbe3f49386708ce999fc4d4da06 PATCH 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/3c6cc9f2ca65b6dd61b1af75452dc0e1cd0aad8d PATCH 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/44bea2032af0425e4ce6d26a8af0ede79db49ec1 PATCH 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/479084ae0e1d9cb7929cb4298d35623de189f80a PATCH 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/4db79a322db8c97f7b73b8a347395ef4d685eb40 PATCH 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/e334cbf3388fd9334503a778a82d9e9f14dd2f71 PATCH 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://access.redhat.com/errata/RHSA-2026:27708 ADVISORY 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://access.redhat.com/errata/RHSA-2026:27731 ADVISORY 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://access.redhat.com/errata/RHSA-2026:27735 ADVISORY 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://access.redhat.com/errata/RHSA-2026:36018 ADVISORY 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://access.redhat.com/errata/RHSA-2026:44230 VENDOR 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://access.redhat.com/errata/RHSA-2026:44231 VENDOR 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://access.redhat.com/errata/RHSA-2026:44259 VENDOR 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://access.redhat.com/errata/RHSA-2026:44262 VENDOR 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://access.redhat.com/errata/RHSA-2026:44270 VENDOR 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://access.redhat.com/errata/RHSA-2026:47727 VENDOR 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://access.redhat.com/errata/RHSA-2026:62639 VENDOR 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://access.redhat.com/errata/RHSA-2026:62640 VENDOR 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://access.redhat.com/errata/RHSA-2026:62641 VENDOR 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://access.redhat.com/errata/RHSA-2026:62642 VENDOR 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://access.redhat.com/security/cve/CVE-2026-46323 ADVISORY 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://bugzilla.redhat.com/show_bug.cgi?id=2479832 ADVISORY 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html REFERENCE 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html REFERENCE 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html REFERENCE 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-46323.json ADVISORY 0b0ca135-0b70-47e7-9f44-1890c2a1c46c