CVE-2026-52943

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-06-24. the CNA's CVSS baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:linux, epss, ghsa
Trending — 4 sources updated this weekElevated
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.8Exploit: Elevated riskExposed: 0

A fix is available — apply it.

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().

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
56(Track)
EG Risk 56/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity78% × 45%
Exploitation40% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
15%
KEV
Not listed

Published

June 24, 2026

Last Modified

August 5, 2026

Advisory Details (8)

Auto-updated Jun 28, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic🟡 PoC Available

net: skbuff: fix missing zerocopy reference in pskb_carve helpers - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/fd470f0a97b8e9a125f520265d2f3b088ffb5b8a
generic🟡 PoC Available

net: skbuff: fix missing zerocopy reference in pskb_carve helpers - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ceafb893b12f23331dcc5ff9587e643c3a40ee9f
generic🟡 PoC Available

net: skbuff: fix missing zerocopy reference in pskb_carve helpers - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/9b40bdc2a3298225dffab8158208a0d8c6300578
generic🟡 PoC Available

net: skbuff: fix missing zerocopy reference in pskb_carve helpers - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/98d0912e9f841e5529a5b89a972805f34cb1c69d
generic🟡 PoC Available

net: skbuff: fix missing zerocopy reference in pskb_carve helpers - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/96a4713ae041cc85e712bac682cd2e644004d6c6
generic🟡 PoC Available

net: skbuff: fix missing zerocopy reference in pskb_carve helpers - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8dbed691e43a50903658130bde0fcb5abc425b37
generic🟡 PoC Available

net: skbuff: fix missing zerocopy reference in pskb_carve helpers - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/474d6c771d798bca84f0a140b611e36743511e18
generic🟡 PoC Available

net: skbuff: fix missing zerocopy reference in pskb_carve helpers - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2e0e74c59b2761a414d9f48d7bee1e45220b2427

Vendor Advisories for CVE-2026-52943(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(8)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-virtual-hwe-26.04-edge (7.0.0-28.28) @ resolute2026-08-25ubuntu
ubuntulinux-tools-oem-7.0 (7.0.0-1009.9) @ resolute2026-08-25ubuntu
ubuntulinux-virtual-hwe-24.04-edge (7.0.0-28.28~24.04.1) @ noble2026-08-25ubuntu
ubuntulinux-tools-oracle-7.0 (7.0.0-1008.8) @ resolute2026-08-25ubuntu
ubuntulinux-tools-azure-fde-7.0 (7.0.0-1009.9) @ resolute2026-08-25ubuntu
ubuntulinux-tools-raspi-realtime-7.0 (7.0.0-1015.15) @ resolute2026-08-25ubuntu
ubuntulinux-tools-nvidia-hwe-24.04-edge (7.0.0-1016.16) @ resolute2026-08-25ubuntu
ubuntulinux-tools-nvidia-hwe-26.04 (7.0.0-2016.16) @ resolute2026-08-25ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(5 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
linux5.10.103-1 ... 5.10.92-2 (54 versions)5.10.259-1—
linux-6.16.1.106-3~deb11u1 ... 6.1.174-1~deb11u1 (20 versions)6.1.176-1~deb11u1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 6.1.99-1 (53 versions)6.1.176-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.94-1~bpo12+1 (27 versions)6.12.94-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 7.0.9-1~bpo13+1 (138 versions)7.0.12-1—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(8)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 33× in last 7d / 160× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 280 total refreshes for this CVE.

  1. 2026-08-25 13:49 UTCEPSS rescore
  2. 2026-08-25 01:29 UTCEG score recompute
  3. 2026-08-25 01:29 UTCVendor advisory
  4. 2026-08-25 01:29 UTCGHSA enrichment
  5. 2026-08-24 13:48 UTCEG score recompute
  6. 2026-08-24 13:48 UTCVendor advisory
  7. 2026-08-24 13:48 UTCGHSA enrichment
  8. 2026-08-24 00:16 UTCVendor advisory
  9. 2026-08-24 00:16 UTCGHSA enrichment
  10. 2026-08-23 12:37 UTCVendor advisory
  11. 2026-08-23 12:37 UTCGHSA enrichment
  12. 2026-08-23 00:59 UTCEG score recompute
  13. 2026-08-23 00:59 UTCVendor advisory
  14. 2026-08-23 00:59 UTCGHSA enrichment
  15. 2026-08-23 00:19 UTCEPSS rescore
  16. 2026-08-22 13:19 UTCEG score recompute
  17. 2026-08-22 13:19 UTCVendor advisory
  18. 2026-08-22 13:19 UTCGHSA enrichment
  19. 2026-08-21 23:49 UTCEPSS rescore
  20. 2026-08-21 19:07 UTCVendor advisory
  21. 2026-08-21 19:07 UTCGHSA enrichment
  22. 2026-08-21 07:19 UTCEG score recompute
  23. 2026-08-21 07:19 UTCVendor advisory
  24. 2026-08-21 07:19 UTCGHSA enrichment
  25. 2026-08-20 22:55 UTCEPSS rescore
Show 75 more
  1. 2026-08-20 19:14 UTCVendor advisory
  2. 2026-08-20 19:14 UTCGHSA enrichment
  3. 2026-08-20 07:36 UTCEG score recompute
  4. 2026-08-20 07:36 UTCVendor advisory
  5. 2026-08-20 07:36 UTCGHSA enrichment
  6. 2026-08-19 17:04 UTCEPSS rescore
  7. 2026-08-19 14:17 UTCVendor advisory
  8. 2026-08-19 14:16 UTCGHSA enrichment
  9. 2026-08-19 02:22 UTCEG score recompute
  10. 2026-08-19 02:22 UTCVendor advisory
  11. 2026-08-19 02:21 UTCGHSA enrichment
  12. 2026-08-18 13:48 UTCEPSS rescore
  13. 2026-08-17 13:47 UTCEPSS rescore
  14. 2026-08-17 07:49 UTCVendor advisory
  15. 2026-08-17 07:49 UTCGHSA enrichment
  16. 2026-08-16 20:09 UTCEG score recompute
  17. 2026-08-16 20:09 UTCVendor advisory
  18. 2026-08-16 20:09 UTCGHSA enrichment
  19. 2026-08-16 14:56 UTCEPSS rescore
  20. 2026-08-16 08:26 UTCEG score recompute
  21. 2026-08-16 08:26 UTCVendor advisory
  22. 2026-08-16 08:26 UTCGHSA enrichment
  23. 2026-08-16 02:14 UTCEPSS rescore
  24. 2026-08-15 20:48 UTCVendor advisory
  25. 2026-08-15 20:48 UTCGHSA enrichment
  26. 2026-08-15 08:43 UTCEG score recompute
  27. 2026-08-15 08:43 UTCVendor advisory
  28. 2026-08-15 08:43 UTCGHSA enrichment
  29. 2026-08-15 01:30 UTCEPSS rescore
  30. 2026-08-14 18:48 UTCVendor advisory
  31. 2026-08-14 18:48 UTCGHSA enrichment
  32. 2026-08-14 07:10 UTCEG score recompute
  33. 2026-08-14 07:10 UTCVendor advisory
  34. 2026-08-14 07:10 UTCGHSA enrichment
  35. 2026-08-13 22:00 UTCEPSS rescore
  36. 2026-08-13 19:31 UTCVendor advisory
  37. 2026-08-13 19:31 UTCGHSA enrichment
  38. 2026-08-13 07:53 UTCVendor advisory
  39. 2026-08-13 07:53 UTCGHSA enrichment
  40. 2026-08-12 20:14 UTCEG score recompute
  41. 2026-08-12 20:14 UTCVendor advisory
  42. 2026-08-12 20:14 UTCGHSA enrichment
  43. 2026-08-12 13:51 UTCEPSS rescore
  44. 2026-08-12 08:36 UTCVendor advisory
  45. 2026-08-12 08:36 UTCGHSA enrichment
  46. 2026-08-11 20:58 UTCEG score recompute
  47. 2026-08-11 20:58 UTCVendor advisory
  48. 2026-08-11 20:58 UTCGHSA enrichment
  49. 2026-08-11 09:19 UTCEG score recompute
  50. 2026-08-11 09:19 UTCVendor advisory
  51. 2026-08-11 09:19 UTCGHSA enrichment
  52. 2026-08-11 00:00 UTCEPSS rescore
  53. 2026-08-10 21:41 UTCVendor advisory
  54. 2026-08-10 21:41 UTCGHSA enrichment
  55. 2026-08-10 10:02 UTCVendor advisory
  56. 2026-08-10 10:02 UTCGHSA enrichment
  57. 2026-08-09 22:24 UTCEG score recompute
  58. 2026-08-09 22:24 UTCVendor advisory
  59. 2026-08-09 22:24 UTCGHSA enrichment
  60. 2026-08-09 13:46 UTCEPSS rescore
  61. 2026-08-09 10:46 UTCVendor advisory
  62. 2026-08-09 10:46 UTCGHSA enrichment
  63. 2026-08-08 23:07 UTCEG score recompute
  64. 2026-08-08 23:07 UTCVendor advisory
  65. 2026-08-08 23:07 UTCGHSA enrichment
  66. 2026-08-08 16:37 UTCEPSS rescore
  67. 2026-08-08 11:29 UTCVendor advisory
  68. 2026-08-08 11:29 UTCGHSA enrichment
  69. 2026-08-07 23:51 UTCEG score recompute
  70. 2026-08-07 23:51 UTCVendor advisory
  71. 2026-08-07 23:51 UTCGHSA enrichment
  72. 2026-08-07 12:12 UTCVendor advisory
  73. 2026-08-07 12:12 UTCGHSA enrichment
  74. 2026-08-07 00:34 UTCEG score recompute
  75. 2026-08-07 00:34 UTCVendor advisory

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCvn-lazyming/CVE-2026-52943
    First seen Jun 16, 2026

    This is a Linux Kernel Local Privilege Escalation PoC code for CVE-2026-52943 a use-after-free in skbuff.c, my first 0day found by me in linux kernel

    Open source ↗

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-52943?
CVE-2026-52943 is a high vulnerability published on June 24, 2026. In the Linux kernel, the following vulnerability has been resolved: net: skbuff: fix missing zerocopy reference in pskb_carve helpers pskbcarveinsideheader() and pskbcarveinsidenonlinear() both copy the old skbsharedinfo header into a new buffer via memcpy(), which includes the destructorarg…
When was CVE-2026-52943 disclosed?
CVE-2026-52943 was first published in the National Vulnerability Database on June 24, 2026, with the most recent update on August 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-52943 actively exploited?
CVE-2026-52943 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 85.4% of all scored CVEs.
What is the CVSS score of CVE-2026-52943?
CVE-2026-52943 has a CVSS v4.0 base score of 7.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-52943?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-52943, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-52943

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