9.8
CRITICAL
CVSS 3.1
CVE-2026-52993
tipc: fix double-free in tipc_buf_append()
Overview
Description
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.
Details
INFO
Published Date :
June 24, 2026, 5:17 p.m.
Last Modified :
July 15, 2026, 1:16 a.m.
Remotely Exploit :
Yes !
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework
for assessing the severity of vulnerabilities in software and systems.
We collect and displays CVSS scores from various sources for each CVE.
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | ||||
| CVSS 3.1 | HIGH | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c |
Solution
Fix a double-free vulnerability in tipc_buf_append by checking for reallocated skbs.
- Apply the patch for the Linux kernel tipc vulnerability.
- Check if head points to a newly allocated skb.
- Reassign *headbuf if the skb was reallocated.
References
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-52993.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-52993 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-52993
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-52993 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-52993 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Jul. 15, 2026
Action Type Old Value New Value Changed Affected [{'cpes': ['cpe:/o:redhat:enterprise_linux:10'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 10', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:8'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:9'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:6'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 6', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:7'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 7', 'defaultStatus': 'unaffected'}] [{'cpes': ['cpe:/o:redhat:enterprise_linux:10'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 10', 'packageName': 'kernel', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:6'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 6', 'packageName': 'kernel', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:7'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 7', 'packageName': 'kernel', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:7'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 7', 'packageName': 'kernel-rt', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:8'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8', 'packageName': 'kernel', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:8'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8', 'packageName': 'kernel-rt', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:9'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9', 'packageName': 'kernel', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:9'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9', 'packageName': 'kernel-rt', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}] -
Initial Analysis by [email protected]
Jul. 14, 2026
Action Type Old Value New Value Added CWE CWE-415 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.141 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.91 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.33 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.0.10 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.175 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.15.209 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.15 up to (excluding) 5.10.258 Added Reference Type kernel.org: https://git.kernel.org/stable/c/0274f24485fc38032d4093e463dc3ff5c7a667c9 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/1d5e589055880fae229e229e1929e087dbe08cf3 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/29940fff14110ca48c5ccc168d121665b51bb778 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/4d104882bc815d4ec666ace9155f5f52715879a6 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/4ee4deadaae7cb2e3d53af0fc889cf92a73413c0 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/a438975a6dcdbd70865978c021650d1485586f0b Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/d293ca716e7d5dffdaecaf6b9b2f857a33dc3d3a Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/d3556656c6daebf8def751c7e71d11dd0a180d24 Types: Patch Added Reference Type redhat-SADP: https://access.redhat.com/security/cve/CVE-2026-52993 Types: Third Party Advisory Added Reference Type redhat-SADP: https://bugzilla.redhat.com/show_bug.cgi?id=2492437 Types: Third Party Advisory Added Reference Type redhat-SADP: https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52993.json Types: Third Party Advisory -
CVE Modified by 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Jun. 30, 2026
Action Type Old Value New Value Added Affected [{'cpes': ['cpe:/o:redhat:enterprise_linux:10'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 10', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:8'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:9'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:6'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 6', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:7'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 7', 'defaultStatus': 'unaffected'}] Added CVSS V3.1 AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-763 Added Reference https://access.redhat.com/security/cve/CVE-2026-52993 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2492437 Added Reference https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52993.json -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 28, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 24, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'd618d09a68e4eed7a435beb2e355250f6f40664a', 'lessThan': 'a438975a6dcdbd70865978c021650d1485586f0b', 'versionType': 'git'}, {'status': 'affected', 'version': 'd618d09a68e4eed7a435beb2e355250f6f40664a', 'lessThan': '4ee4deadaae7cb2e3d53af0fc889cf92a73413c0', 'versionType': 'git'}, {'status': 'affected', 'version': 'd618d09a68e4eed7a435beb2e355250f6f40664a', 'lessThan': 'd3556656c6daebf8def751c7e71d11dd0a180d24', 'versionType': 'git'}, {'status': 'affected', 'version': 'd618d09a68e4eed7a435beb2e355250f6f40664a', 'lessThan': '0274f24485fc38032d4093e463dc3ff5c7a667c9', 'versionType': 'git'}, {'status': 'affected', 'version': 'd618d09a68e4eed7a435beb2e355250f6f40664a', 'lessThan': '4d104882bc815d4ec666ace9155f5f52715879a6', 'versionType': 'git'}, {'status': 'affected', 'version': 'd618d09a68e4eed7a435beb2e355250f6f40664a', 'lessThan': '1d5e589055880fae229e229e1929e087dbe08cf3', 'versionType': 'git'}, {'status': 'affected', 'version': 'd618d09a68e4eed7a435beb2e355250f6f40664a', 'lessThan': '29940fff14110ca48c5ccc168d121665b51bb778', 'versionType': 'git'}, {'status': 'affected', 'version': 'd618d09a68e4eed7a435beb2e355250f6f40664a', 'lessThan': 'd293ca716e7d5dffdaecaf6b9b2f857a33dc3d3a', 'versionType': 'git'}], 'programFiles': ['net/tipc/msg.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4.15'}, {'status': 'unaffected', 'version': '0', 'lessThan': '4.15', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.258', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.209', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.175', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.141', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.91', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.33', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.0.10', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/tipc/msg.c'], 'defaultStatus': 'affected'}] Added Description 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. Added Reference https://git.kernel.org/stable/c/0274f24485fc38032d4093e463dc3ff5c7a667c9 Added Reference https://git.kernel.org/stable/c/1d5e589055880fae229e229e1929e087dbe08cf3 Added Reference https://git.kernel.org/stable/c/29940fff14110ca48c5ccc168d121665b51bb778 Added Reference https://git.kernel.org/stable/c/4d104882bc815d4ec666ace9155f5f52715879a6 Added Reference https://git.kernel.org/stable/c/4ee4deadaae7cb2e3d53af0fc889cf92a73413c0 Added Reference https://git.kernel.org/stable/c/a438975a6dcdbd70865978c021650d1485586f0b Added Reference https://git.kernel.org/stable/c/d293ca716e7d5dffdaecaf6b9b2f857a33dc3d3a Added Reference https://git.kernel.org/stable/c/d3556656c6daebf8def751c7e71d11dd0a180d24
EPSS is a daily estimate of the probability of exploitation activity
being observed over the next 30 days. Following chart shows the EPSS
score history of the vulnerability.