CVE-2026-52943

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-06-24. a secondary CVSS source baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Elevated
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 7.8Exploit: Elevated riskExposed services: Not assessed

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
7.8HIGHmedium confidence
EG Risk
56
EG Risk 56/100

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%
EPSS PROB
0.2%
EPSS %ILE
13th
KEV
Not listed

Published

June 24, 2026

Last Modified

September 8, 2026

Advisory Details (8)

Auto-updated Jun 28, 2026
🔬 Proof of concept available. Patch available.
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(10)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulinux-virtual-hwe-26.04-edge (7.0.0-28.28) @ resolute2026-09-23ubuntu
ubuntulinux-tools-oem-7.0 (7.0.0-1009.9) @ resolute2026-09-23ubuntu
ubuntulinux-virtual-hwe-24.04-edge (7.0.0-28.28~24.04.1) @ noble2026-09-23ubuntu
ubuntulinux-tools-oracle-7.0 (7.0.0-1008.8) @ resolute2026-09-23ubuntu
ubuntulinux-tools-azure-fde-7.0 (7.0.0-1009.9) @ resolute2026-09-23ubuntu
ubuntulinux-tools-raspi-realtime-7.0 (7.0.0-1015.15) @ resolute2026-09-23ubuntu
ubuntulinux-tools-nvidia-hwe-24.04-edge (7.0.0-1016.16) @ resolute2026-09-23ubuntu
ubuntulinux-tools-nvidia-hwe-26.04 (7.0.0-2016.16) @ resolute2026-09-23ubuntu
ubuntulinux-tools-gcp-edge (7.0.0-1011.11~24.04.1) @ noble2026-09-23ubuntu
ubuntulinux-tools-azure-edge (7.0.0-1014.14~24.04.1) @ noble2026-09-23ubuntu

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 rangeFix by version rangeDependents
linux5.10.103-1 ... 5.10.92-2 (54 versions)
  • every version up to 5.10.259-1: fixed in 5.10.259-1
—
linux-6.16.1.106-3~deb11u1 ... 6.1.174-1~deb11u1 (20 versions)
  • every version up to 6.1.176-1~deb11u1: fixed in 6.1.176-1~deb11u1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.106-1 ... 6.1.99-1 (53 versions)
  • every version up to 6.1.176-1: fixed in 6.1.176-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.38-1 ... 6.12.94-1~bpo12+1 (27 versions)
  • every version up to 6.12.94-1: fixed in 6.12.94-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.0.9-1~bpo13+1 (142 versions)
  • every version up to 7.0.12-1: fixed in 7.0.12-1
—

Weakness Classification(2)

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

Additional Vendor Advisories

(10)

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 7× in last 7d / 34× 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 339 total refreshes for this CVE.

  1. 2026-10-09 20:07 UTCEPSS rescore
  2. 2026-10-08 17:12 UTCEPSS rescore
  3. 2026-10-07 23:48 UTCEPSS rescore
  4. 2026-10-06 15:18 UTCEPSS rescore
  5. 2026-10-05 17:43 UTCEPSS rescore
  6. 2026-10-04 23:22 UTCEPSS rescore
  7. 2026-10-03 14:26 UTCEPSS rescore
  8. 2026-10-02 17:56 UTCEPSS rescore
  9. 2026-10-01 19:50 UTCEPSS rescore
  10. 2026-09-30 15:03 UTCEPSS rescore
  11. 2026-09-29 15:22 UTCEPSS rescore
  12. 2026-09-28 13:51 UTCEPSS rescore
  13. 2026-09-27 13:48 UTCEPSS rescore
  14. 2026-09-26 15:59 UTCEPSS rescore
  15. 2026-09-26 00:27 UTCEPSS rescore
  16. 2026-09-23 17:53 UTCEPSS rescore
  17. 2026-09-23 11:49 UTCEG score recompute
  18. 2026-09-23 11:49 UTCVendor advisory
  19. 2026-09-23 11:49 UTCGHSA enrichment
  20. 2026-09-20 20:16 UTCEPSS rescore
  21. 2026-09-18 19:28 UTCEPSS rescore
  22. 2026-09-18 08:15 UTCEG score recompute
  23. 2026-09-18 08:15 UTCVendor advisory
  24. 2026-09-18 08:15 UTCGHSA enrichment
  25. 2026-09-16 14:08 UTCEPSS rescore
Show 75 more
  1. 2026-09-16 05:15 UTCEPSS rescore
  2. 2026-09-14 01:58 UTCEG score recompute
  3. 2026-09-14 01:58 UTCVendor advisory
  4. 2026-09-14 01:58 UTCGHSA enrichment
  5. 2026-09-13 16:47 UTCEPSS rescore
  6. 2026-09-13 12:11 UTCEG score recompute
  7. 2026-09-13 12:11 UTCVendor advisory
  8. 2026-09-13 12:11 UTCGHSA enrichment
  9. 2026-09-11 14:53 UTCEPSS rescore
  10. 2026-09-10 09:35 UTCEPSS rescore
  11. 2026-09-08 22:01 UTCEPSS rescore
  12. 2026-09-08 09:44 UTCEG score recompute
  13. 2026-09-08 09:44 UTCVendor advisory
  14. 2026-09-08 09:44 UTCGHSA enrichment
  15. 2026-09-08 08:59 UTCEG score recompute
  16. 2026-09-08 08:59 UTCVendor advisory
  17. 2026-09-08 08:59 UTCGHSA enrichment
  18. 2026-09-07 16:01 UTCEPSS rescore
  19. 2026-09-06 13:47 UTCEPSS rescore
  20. 2026-09-04 05:06 UTCEPSS rescore
  21. 2026-09-02 14:12 UTCEPSS rescore
  22. 2026-09-01 13:54 UTCEPSS rescore
  23. 2026-09-01 04:40 UTCEPSS rescore
  24. 2026-08-30 20:21 UTCEG score recompute
  25. 2026-08-30 20:21 UTCVendor advisory
  26. 2026-08-30 20:21 UTCGHSA enrichment
  27. 2026-08-30 19:17 UTCEPSS rescore
  28. 2026-08-30 01:22 UTCEPSS rescore
  29. 2026-08-28 21:41 UTCEPSS rescore
  30. 2026-08-28 04:51 UTCEG score recompute
  31. 2026-08-28 04:51 UTCVendor advisory
  32. 2026-08-28 04:51 UTCGHSA enrichment
  33. 2026-08-27 14:25 UTCEPSS rescore
  34. 2026-08-26 14:46 UTCEPSS rescore
  35. 2026-08-25 13:49 UTCEPSS rescore
  36. 2026-08-25 01:29 UTCEG score recompute
  37. 2026-08-25 01:29 UTCVendor advisory
  38. 2026-08-25 01:29 UTCGHSA enrichment
  39. 2026-08-24 13:48 UTCEG score recompute
  40. 2026-08-24 13:48 UTCVendor advisory
  41. 2026-08-24 13:48 UTCGHSA enrichment
  42. 2026-08-24 00:16 UTCVendor advisory
  43. 2026-08-24 00:16 UTCGHSA enrichment
  44. 2026-08-23 12:37 UTCVendor advisory
  45. 2026-08-23 12:37 UTCGHSA enrichment
  46. 2026-08-23 00:59 UTCEG score recompute
  47. 2026-08-23 00:59 UTCVendor advisory
  48. 2026-08-23 00:59 UTCGHSA enrichment
  49. 2026-08-23 00:19 UTCEPSS rescore
  50. 2026-08-22 13:19 UTCEG score recompute
  51. 2026-08-22 13:19 UTCVendor advisory
  52. 2026-08-22 13:19 UTCGHSA enrichment
  53. 2026-08-21 23:49 UTCEPSS rescore
  54. 2026-08-21 19:07 UTCVendor advisory
  55. 2026-08-21 19:07 UTCGHSA enrichment
  56. 2026-08-21 07:19 UTCEG score recompute
  57. 2026-08-21 07:19 UTCVendor advisory
  58. 2026-08-21 07:19 UTCGHSA enrichment
  59. 2026-08-20 22:55 UTCEPSS rescore
  60. 2026-08-20 19:14 UTCVendor advisory
  61. 2026-08-20 19:14 UTCGHSA enrichment
  62. 2026-08-20 07:36 UTCEG score recompute
  63. 2026-08-20 07:36 UTCVendor advisory
  64. 2026-08-20 07:36 UTCGHSA enrichment
  65. 2026-08-19 17:04 UTCEPSS rescore
  66. 2026-08-19 14:17 UTCVendor advisory
  67. 2026-08-19 14:16 UTCGHSA enrichment
  68. 2026-08-19 02:22 UTCEG score recompute
  69. 2026-08-19 02:22 UTCVendor advisory
  70. 2026-08-19 02:21 UTCGHSA enrichment
  71. 2026-08-18 13:48 UTCEPSS rescore
  72. 2026-08-17 13:47 UTCEPSS rescore
  73. 2026-08-17 07:49 UTCVendor advisory
  74. 2026-08-17 07:49 UTCGHSA enrichment
  75. 2026-08-16 20:09 UTCEG score recompute

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 on June 24, 2026, with the most recent update on September 8, 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 0.2% probability of exploitation in the next 30 days (13th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-52943?
CVE-2026-52943 has a CVSS base score of 7.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-52943?
A fix for CVE-2026-52943 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-52943 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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