CVE-2026-52943: net: skbuff: fix missing zerocopy reference in pskb_carve helpers
Noroxi assessment
Priority: Monitor (action score 31/100)
- Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.30% (FIRST EPSS).
- Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: Linux Linux 2e0e74c59b2761a414d9f48d7bee1e45220b2427, 474d6c771d798bca84f0a140b611e36743511e18, 8dbed691e43a50903658130bde0fcb5abc425b37; azl3 kernel 6.6.141.1-1 on Azure Linux 3.0 6.6.143.1-1.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to Linux Linux 2e0e74c59b2761a414d9f48d7bee1e45220b2427, 474d6c771d798bca84f0a140b611e36743511e18, 8dbed691e43a50903658130bde0fcb5abc425b37; azl3 kernel 6.6.141.1-1 on Azure Linux 3.0 6.6.143.1-1 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
In the Linux kernel, the following vulnerability has been resolved: net: skbuff: fix missing zerocopy reference in pskb_carve helpers pskb_carve_inside_header() and pskb_carve_inside_nonlinear() both copy the old skb_shared_info header into a new buffer via memcpy(), which includes the destructor_arg pointer (uarg) for MSG_ZEROCOPY skbs. Neither function calls net_zcopy_get() for the new shinfo, creating an unaccounted holder: every skb_shared_info with destructor_arg set will call skb_zcopy_clear() once when freed, but the corresponding net_zcopy_get() was never called for the new copy. Repeated calls drive uarg->refcnt to zero prematurely, freeing ubuf_info_msgzc while TX skbs still hold live destructor_arg pointers. KASAN reports use-after-free on a freed ubuf_info_msgzc: BUG: KASAN: slab-use-after-free in skb_release_data+0x77b/0x810 Read of size 8 at addr ffff88801574d3e8 by task poc/220 Call Trace: skb_release_data+0x77b/0x810 kfree_skb_list_reason+0x13e/0x610 skb_release_data+0x4cd/0x810 sk_skb_reason_drop+0xf3/0x340 skb_queue_purge_reason+0x282/0x440 rds_tcp_inc_free+0x1e/0x30 rds_recvmsg+0x354/0x1780 __sys_recvmsg+0xdf/0x180 Allocated by task 219: msg_zerocopy_realloc+0x157/0x7b0 tcp_sendmsg_locked+0x2892/0x3ba0 Freed by task 219: ip_recv_error+0x74a/0xb10 tcp_recvmsg+0x475/0x530 The skb consuming the late access still referenced the same uarg via shinfo->destructor_arg copied by pskb_carve_inside_nonlinear() without a refcount bump. This has been verified to be reliably exploitable: a working proof-of-concept achieves full root privilege escalation from an unprivileged local user on a default kernel configuration. The fix follows the pattern of pskb_expand_head() which has the same memcpy/cloned structure. For pskb_carve_inside_header(), net_zcopy_get() is placed after skb_orphan_frags() succeeds, so the orphan error path needs no cleanup. For pskb_carve_inside_nonlinear(), net_zcopy_get() is placed after all failure points and just before skb_release_data(), so no error path needs cleanup at all -- matching pskb_expand_head() more closely and avoiding the need for a balancing net_zcopy_put().
- BDU:2026-09715
- SUSE-SU-2026:22598-1
- SUSE-SU-2026:22672-1
- SUSE-SU-2026:22678-1
- SUSE-SU-2026:22679-1
- SUSE-SU-2026:22684-1
- SUSE-SU-2026:22685-1
- SUSE-SU-2026:22686-1
- SUSE-SU-2026:22687-1
- SUSE-SU-2026:22692-1
- SUSE-SU-2026:22693-1
- SUSE-SU-2026:22694-1
- SUSE-SU-2026:22695-1
- SUSE-SU-2026:22697-1
- SUSE-SU-2026:22698-1
- SUSE-SU-2026:22710-1
- SUSE-SU-2026:22714-1
- SUSE-SU-2026:22715-1
- SUSE-SU-2026:22716-1
- SUSE-SU-2026:22717-1
- Published
- Jun 24, 2026
- Updated
- Nov 10, 2026
- EPSS
- 0.3% · 23th percentile
- CWE
- CWE-416
Report tools
Action score
31
Low priority for now.
- CVSS
- 31 / 40 · 7.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.3%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · Linux
- 7.8
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- Proof of concept exists, no weaponized module
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Is your version affected? Check itNoroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| linux | linux kernel | cpe:2.3:o:linux:linux_kernel |
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 4.7affected
- 6fa01ccd883021105e9f8af7d04b9f156fa3494a and later · before 8dbed691e43a50903658130bde0fcb5abc425b37affected · git
- 6fa01ccd883021105e9f8af7d04b9f156fa3494a and later · before 9b40bdc2a3298225dffab8158208a0d8c6300578affected · git
- 6fa01ccd883021105e9f8af7d04b9f156fa3494a and later · before fd470f0a97b8e9a125f520265d2f3b088ffb5b8aaffected · git
- 6fa01ccd883021105e9f8af7d04b9f156fa3494a and later · before ceafb893b12f23331dcc5ff9587e643c3a40ee9faffected · git
- 6fa01ccd883021105e9f8af7d04b9f156fa3494a and later · before 2e0e74c59b2761a414d9f48d7bee1e45220b2427affected · git
- 6fa01ccd883021105e9f8af7d04b9f156fa3494a and later · before 96a4713ae041cc85e712bac682cd2e644004d6c6affected · git
- 6fa01ccd883021105e9f8af7d04b9f156fa3494a and later · before 474d6c771d798bca84f0a140b611e36743511e18affected · git
- 6fa01ccd883021105e9f8af7d04b9f156fa3494a and later · before 98d0912e9f841e5529a5b89a972805f34cb1c69daffected · git
- before 4.7not affected · semver
Affected versions · NVD (8)
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- linux linux kernel4.7 and later · before 5.10.259
- linux linux kernel5.11 and later · before 5.15.210
- linux linux kernel5.16 and later · before 6.1.176
- linux linux kernel6.2 and later · before 6.6.143
- linux linux kernel6.7 and later · before 6.12.93
- linux linux kernel6.13 and later · before 6.18.35
- linux linux kernel6.19 and later · before 7.0.12
- linux linux kernel7.1
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | before 6.1.176-1 | 6.1.176-1 |
| Debian:13 | linux | before 6.12.94-1 | 6.12.94-1 |
| Debian:14 | linux | before 7.0.12-1 | 7.0.12-1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-64kb | before 5.14.21-150400.24.228.1 | 5.14.21-150400.24.228.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-docs | before 5.14.21-150400.24.228.1 | 5.14.21-150400.24.228.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-obs-build | before 5.14.21-150400.24.228.1 | 5.14.21-150400.24.228.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-syms | before 5.14.21-150400.24.228.1 | 5.14.21-150400.24.228.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS | kernel-64kb | before 5.14.21-150500.55.177.1 | 5.14.21-150500.55.177.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS | kernel-docs | before 5.14.21-150500.55.177.1 | 5.14.21-150500.55.177.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS | kernel-obs-build | before 5.14.21-150500.55.177.1 | 5.14.21-150500.55.177.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS | kernel-syms | before 5.14.21-150500.55.177.1 | 5.14.21-150500.55.177.1 |
| SUSE:Linux Enterprise Live Patching 15 SP4 | kernel-livepatch-SLE15-SP4_Update_49 | before 6-150400.2.1 | 6-150400.2.1 |
| SUSE:Linux Enterprise Live Patching 15 SP4 | kernel-livepatch-SLE15-SP4_Update_51 | before 5-150400.2.1 | 5-150400.2.1 |
| SUSE:Linux Enterprise Live Patching 15 SP4 | kernel-livepatch-SLE15-SP4_Update_52 | before 4-150400.2.1 | 4-150400.2.1 |
| SUSE:Linux Enterprise Live Patching 15 SP4 | kernel-livepatch-SLE15-SP4_Update_54 | before 2-150400.2.1 | 2-150400.2.1 |
| SUSE:Linux Enterprise Live Patching 15 SP4 | kernel-livepatch-SLE15-SP4_Update_55 | before 2-150400.2.1 | 2-150400.2.1 |
| SUSE:Linux Enterprise Live Patching 15 SP4 | kernel-livepatch-SLE15-SP4_Update_56 | before 2-150400.2.1 | 2-150400.2.1 |
| SUSE:Linux Enterprise Live Patching 15 SP4 | kernel-livepatch-SLE15-SP4_Update_57 | before 1-150400.9.3.1 | 1-150400.9.3.1 |
| SUSE:Linux Enterprise Live Patching 15 SP5 | kernel-livepatch-SLE15-SP5_Update_40 | before 2-150500.2.2 | 2-150500.2.2 |
| SUSE:Linux Enterprise Live Patching 15 SP5 | kernel-livepatch-SLE15-SP5_Update_41 | before 2-150500.2.2 | 2-150500.2.2 |
| SUSE:Linux Enterprise Live Patching 15 SP5 | kernel-livepatch-SLE15-SP5_Update_42 | before 2-150500.2.2 | 2-150500.2.2 |
| SUSE:Linux Enterprise Live Patching 15 SP5 | kernel-livepatch-SLE15-SP5_Update_43 | before 1-150500.11.5.1 | 1-150500.11.5.1 |
| SUSE:Linux Enterprise Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_26 | before 3-150600.2.2 | 3-150600.2.2 |
| SUSE:Linux Enterprise Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_27 | before 2-150600.2.2 | 2-150600.2.2 |
+49
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV90Now
- CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV89Now
- CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV85Now
Published before and after this one in the same product
- ← EarlierCVE-2026-52941Jun 24, 2026 · net/smc: avoid NULL deref of conn->lnk in smc_msg_event tracepoint22Monitor
- ← EarlierCVE-2026-52942Jun 24, 2026 · netfilter: nf_log: validate MAC header was set before dumping it28Monitor
- Later →CVE-2026-52952Jun 24, 2026 · iommu: Fix WARN_ON in __iommu_group_set_domain_nofail() due to reset35Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 2e0e74c59b2761a414d9f48d7bee1e45220b2427 | Vendor (CNA) |
| Linux Linux | 474d6c771d798bca84f0a140b611e36743511e18 | Vendor (CNA) |
| Linux Linux | 8dbed691e43a50903658130bde0fcb5abc425b37 | Vendor (CNA) |
| Linux Linux | 96a4713ae041cc85e712bac682cd2e644004d6c6 | Vendor (CNA) |
| Linux Linux | 98d0912e9f841e5529a5b89a972805f34cb1c69d | Vendor (CNA) |
| Linux Linux | 9b40bdc2a3298225dffab8158208a0d8c6300578 | Vendor (CNA) |
| Linux Linux | ceafb893b12f23331dcc5ff9587e643c3a40ee9f | Vendor (CNA) |
| Linux Linux | fd470f0a97b8e9a125f520265d2f3b088ffb5b8a | Vendor (CNA) |
| azl3 kernel 6.6.141.1-1 on Azure Linux 3.0 | 6.6.143.1-1 · CBL-Mariner Releases | Microsoft (MSRC) |
| debian:linux | 6.1.176-1 · Debian:12 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0_Update_18 | 6-1.1 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0_Update_19 | 4-1.1 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0_Update_20 | 3-1.1 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0_Update_21 | 3-1.1 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0_Update_22 | 3-1.1 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0_Update_23 | 3-1.1 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0_Update_24 | 2-1.1 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0-RT_Update_19 | 6-1.1 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0-RT_Update_20 | 4-1.1 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0-RT_Update_21 | 3-1.1 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0-RT_Update_22 | 3-1.2 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-SLE16-RT_Update_9 | 4-160000.1.1 · SUSE:Linux Micro 6.2 | Package registry (OSV) |
Exploit status
Proof of concept available
A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.
Evidence
- Proof-of-concept repository on GitHub ×1
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Proof-of-concept repository on GitHub | stars:8 | 2026-06-16 |
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- First PoC-8 d
- Published
- TodayNov 14, 2026+143 d
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-0440 · Jun 25, 2026(Linux Kernel Güvenlik Bildirimi)
Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-416 · Use After FreeCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvd-secondary
Root cause
After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.
The bug in code
The whole CWE-416 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
free(dev->buf);
/* ... another thread is still running ... */
process(dev->buf);Fixed
lock(&dev->lock);
free(dev->buf);
dev->buf = NULL;
unlock(&dev->lock);Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log (2)
- SSVC exploitation— → none
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (13 more)Show less
- git.kernel.org/stable/c/474d6c771d798bca84f0a140b611e36743511e18
- git.kernel.org/stable/c/8dbed691e43a50903658130bde0fcb5abc425b37
- git.kernel.org/stable/c/96a4713ae041cc85e712bac682cd2e644004d6c6
- git.kernel.org/stable/c/98d0912e9f841e5529a5b89a972805f34cb1c69d
- git.kernel.org/stable/c/9b40bdc2a3298225dffab8158208a0d8c6300578
- git.kernel.org/stable/c/ceafb893b12f23331dcc5ff9587e643c3a40ee9f
- git.kernel.org/stable/c/fd470f0a97b8e9a125f520265d2f3b088ffb5b8a
- access.redhat.com/security/cve/CVE-2026-52943
- bugzilla.redhat.com/show_bug.cgi?id=2492137
- cert-portal.siemens.com/productcert/html/ssa-019113.html
- cert-portal.siemens.com/productcert/html/ssa-457936.html
- cert-portal.siemens.com/productcert/html/ssa-784472.html
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52943.json
Vendor advisories and official records. Exploit/PoC links are deliberately left out.