CVE-2026-52993

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-06-24. a secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — Patch released this week
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.8Exploit: None knownExposed: 0

A fix is available — apply it.

In the Linux kernel, the following vulnerability has been resolved:

tipc: fix double-free in tipc_buf_append()

tipc_msg_validate() can potentially reallocate the skb it is validating, freeing the old one. In tipc_buf_append(), it was being called with a pointer to a local variable which was a copy of the caller's skb pointer.

If the skb was reallocated and validation subsequently failed, the error handling path would free the original skb pointer, which had already been freed, leading to double-free.

Fix this by checking if head now points to a newly allocated reassembled skb. If it does, reassign *headbuf for later freeing operations.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity98% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
28%
KEV
Not listed

Published

June 24, 2026

Last Modified

July 24, 2026

Advisory Details (11)

Auto-updated Jul 25, 2026
Patch available. Sources: redhat.
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-52993
redhat Patch Available

Affected: Red Hat Enterprise Linux 8.10 Extended Update Support.

https://access.redhat.com/errata/RHSA-2026:45115
generic

tipc: fix double-free in tipc_buf_append() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/d3556656c6daebf8def751c7e71d11dd0a180d24
generic

tipc: fix double-free in tipc_buf_append() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/d293ca716e7d5dffdaecaf6b9b2f857a33dc3d3a
generic

tipc: fix double-free in tipc_buf_append() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a438975a6dcdbd70865978c021650d1485586f0b
generic

tipc: fix double-free in tipc_buf_append() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4ee4deadaae7cb2e3d53af0fc889cf92a73413c0
generic

tipc: fix double-free in tipc_buf_append() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4d104882bc815d4ec666ace9155f5f52715879a6
generic

tipc: fix double-free in tipc_buf_append() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/29940fff14110ca48c5ccc168d121665b51bb778
generic

tipc: fix double-free in tipc_buf_append() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1d5e589055880fae229e229e1929e087dbe08cf3
generic

tipc: fix double-free in tipc_buf_append() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0274f24485fc38032d4093e463dc3ff5c7a667c9
redhat

2492437 – (CVE-2026-52993) CVE-2026-52993 kernel: tipc: fix double-free in tipc_buf_append()

https://bugzilla.redhat.com/show_bug.cgi?id=2492437

Vendor Advisories for CVE-2026-52993(4)

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

Patch Availability(23)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-oracle-lts-22.04 (5.15.0.1109.105) @ jammy2026-07-27ubuntu
ubuntulinux-virtual-hwe-24.04-edge (7.0.0-28.28~24.04.1) @ noble2026-07-27ubuntu
ubuntulinux-tools-gcp-fips-6.8 (6.8.0-1064.72+fips1) @ noble2026-07-27ubuntu
ubuntulinux-virtual-hwe-20.04-edge (5.15.0.186.196~20.04.1) @ focal2026-07-27ubuntu
ubuntulinux-tools-nvidia-tegra-rt-5.15 (5.15.0.1064.66~20.04.1) @ focal2026-07-27ubuntu
ubuntulinux-tools-oracle-7.0 (7.0.0-1008.8) @ resolute2026-07-27ubuntu
ubuntulinux-tools-lowlatency-hwe-22.04-edge (6.8.0-136.136.2~22.04.1) @ jammy2026-07-27ubuntu
ubuntulinux-tools-oracle-edge (6.8.0-1058.61~22.04.1) @ jammy2026-07-27ubuntu
ubuntulinux-tools-nvidia-lowlatency-64k-6.8 (6.8.0-1059.62.1) @ noble2026-07-27ubuntu
ubuntulinux-virtual-hwe-26.04-edge (7.0.0-28.28) @ resolute2026-07-27ubuntu
ubuntulinux-tools-nvidia-tegra-rt-5.15 (5.15.0.1064.64) @ jammy2026-07-27ubuntu
ubuntulinux-tools-azure-fde-7.0 (7.0.0-1009.9) @ resolute2026-07-27ubuntu
ubuntulinux-tools-aws-lts-24.04 (6.8.0-1061.64+1) @ noble2026-07-27ubuntu
ubuntulinux-tools-azure-lts-24.04 (6.8.0-1063.71) @ noble2026-07-27ubuntu
ubuntulinux-tools-azure-fde-lts-22.04 (5.15.0.1117.126) @ jammy2026-07-27ubuntu
ubuntulinux-tools-azure-fde-lts-24.04 (6.8.0-1062.69) @ noble2026-07-27ubuntu
ubuntulinux-tools-azure-fde-6.8 (6.8.0-1062.69~22.04.1) @ jammy2026-07-27ubuntu
ubuntulinux-tools-azure-fips-6.8 (6.8.0-1063.71+fips2) @ noble2026-07-27ubuntu
ubuntulinux-tools-oem-7.0 (7.0.0-1009.9) @ resolute2026-07-27ubuntu
ubuntulinux-tools-nvidia-lowlatency-5.15 (5.15.0.1107.107) @ jammy2026-07-27ubuntu
ubuntulinux-virtual-6.8 (6.8.0-136.136) @ noble2026-07-27ubuntu
redhatkernel-rt-0:4.18.0-553.147.1.rt7.488.el8_102026-07-24redhat
redhatkernel-0:4.18.0-553.147.1.el8_102026-07-24redhat

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.

Weakness Classification(2)

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

Additional Vendor Advisories

(21)

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 22× in last 7d / 189× 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 193 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-52993?
CVE-2026-52993 is a critical vulnerability published on June 24, 2026. In the Linux kernel, the following vulnerability has been resolved: tipc: fix double-free in tipcbufappend() tipcmsgvalidate() can potentially reallocate the skb it is validating, freeing the old one. In tipcbufappend(), it was being called with a pointer to a local variable which was a copy of the…
When was CVE-2026-52993 disclosed?
CVE-2026-52993 was first published in the National Vulnerability Database on June 24, 2026, with the most recent update on July 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-52993 actively exploited?
CVE-2026-52993 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 71.9% of all scored CVEs.
What is the CVSS score of CVE-2026-52993?
CVE-2026-52993 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-52993?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-52993, 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.

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