8.8
HIGH
CVSS 3.1
CVE-2026-63829
net: ip_gre: require CAP_NET_ADMIN in the device netns for changelink
Overview
Description
In the Linux kernel, the following vulnerability has been resolved: net: ip_gre: require CAP_NET_ADMIN in the device netns for changelink A tunnel changelink() operates on at most two netns, dev_net(dev) and the tunnel link netns t->net. They differ once the device is created in or moved to a netns other than the one the request runs in. The rtnl changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a caller privileged there but not in t->net can rewrite a tunnel that lives in t->net. Add rtnl_dev_link_net_capable() next to rtnl_get_net_ns_capable() in net/core/rtnetlink.c. It requires CAP_NET_ADMIN in the link netns and is skipped when the link netns is dev_net(dev), where the rtnl path already checked it. The other patches in this series use the same helper. Gate ipgre_changelink() and erspan_changelink() with it, at the top of the op before any attribute is parsed, because the parsers update live tunnel fields first. ipgre_netlink_parms() sets t->collect_md before ip_tunnel_changelink() runs. Commit 8b484efd5cb4 ("ip6: vti: Use ip6_tnl.net in vti6_siocdevprivate().") added the same check on the ioctl path. This adds it on RTM_NEWLINK.
Details
INFO
Published Date :
July 19, 2026, 12:16 p.m.
Last Modified :
Aug. 17, 2026, 5:17 a.m.
Remotely Exploit :
No
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 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
Update the Linux kernel to enforce CAP_NET_ADMIN in the correct network namespace for tunnel operations.
- Apply the kernel patch addressing the CAP_NET_ADMIN check.
- Recompile and install the updated Linux kernel.
- Reboot the system to apply kernel changes.
- Verify the fix by testing tunnel changelink operations.
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-2026-63829.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-63829 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-2026-63829
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-2026-63829 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-63829 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 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 17, 2026
Action Type Old Value New Value Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '19275943d8fe903eb7b9aa53e380e41efd042ada', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '866b0f5ae599490bd496fd84581c68ac8b94e6af', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '92b766fc55156e0da2ecd0c2302c971118f8a229', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': 'e54c05ed3d9c28733fb9e5837219aca3691defa3', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '9831bc9ecb402957810c2045c663fbfe9b09e296', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '1697957eb0971d420dde42862b88eb43506a1105', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '47b5d3d506609b08b2e1f7c14f0b681a1953d572', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '8165f7ff57d9667d2bb477ef6af83ede7fed4ad7', 'versionType': 'git'}], 'programFiles': ['include/net/rtnetlink.h', 'net/core/rtnetlink.c', 'net/ipv4/ip_gre.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '3.16'}, {'status': 'unaffected', 'version': '0', 'lessThan': '3.16', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.261', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.212', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.178', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.95', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.38', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.3', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['include/net/rtnetlink.h', 'net/core/rtnetlink.c', 'net/ipv4/ip_gre.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '19275943d8fe903eb7b9aa53e380e41efd042ada', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '866b0f5ae599490bd496fd84581c68ac8b94e6af', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '92b766fc55156e0da2ecd0c2302c971118f8a229', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': 'e54c05ed3d9c28733fb9e5837219aca3691defa3', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '9831bc9ecb402957810c2045c663fbfe9b09e296', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '1697957eb0971d420dde42862b88eb43506a1105', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '47b5d3d506609b08b2e1f7c14f0b681a1953d572', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '8165f7ff57d9667d2bb477ef6af83ede7fed4ad7', 'versionType': 'git'}], 'programFiles': ['include/net/rtnetlink.h', 'net/core/rtnetlink.c', 'net/ipv4/ip_gre.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '3.16'}, {'status': 'unaffected', 'version': '0', 'lessThan': '3.16', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.261', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.212', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.178', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.95', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.38', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.3', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['include/net/rtnetlink.h', 'net/core/rtnetlink.c', 'net/ipv4/ip_gre.c'], 'defaultStatus': 'affected'}] -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 24, 2026
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/19275943d8fe903eb7b9aa53e380e41efd042ada Added Reference https://git.kernel.org/stable/c/866b0f5ae599490bd496fd84581c68ac8b94e6af Added Reference https://git.kernel.org/stable/c/92b766fc55156e0da2ecd0c2302c971118f8a229 Added Reference https://git.kernel.org/stable/c/e54c05ed3d9c28733fb9e5837219aca3691defa3 Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '9831bc9ecb402957810c2045c663fbfe9b09e296', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '1697957eb0971d420dde42862b88eb43506a1105', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '47b5d3d506609b08b2e1f7c14f0b681a1953d572', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '8165f7ff57d9667d2bb477ef6af83ede7fed4ad7', 'versionType': 'git'}], 'programFiles': ['include/net/rtnetlink.h', 'net/core/rtnetlink.c', 'net/ipv4/ip_gre.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '3.16'}, {'status': 'unaffected', 'version': '0', 'lessThan': '3.16', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.95', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.38', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.3', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['include/net/rtnetlink.h', 'net/core/rtnetlink.c', 'net/ipv4/ip_gre.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '19275943d8fe903eb7b9aa53e380e41efd042ada', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '866b0f5ae599490bd496fd84581c68ac8b94e6af', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '92b766fc55156e0da2ecd0c2302c971118f8a229', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': 'e54c05ed3d9c28733fb9e5837219aca3691defa3', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '9831bc9ecb402957810c2045c663fbfe9b09e296', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '1697957eb0971d420dde42862b88eb43506a1105', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '47b5d3d506609b08b2e1f7c14f0b681a1953d572', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '8165f7ff57d9667d2bb477ef6af83ede7fed4ad7', 'versionType': 'git'}], 'programFiles': ['include/net/rtnetlink.h', 'net/core/rtnetlink.c', 'net/ipv4/ip_gre.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '3.16'}, {'status': 'unaffected', 'version': '0', 'lessThan': '3.16', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.261', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.212', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.178', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.95', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.38', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.3', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['include/net/rtnetlink.h', 'net/core/rtnetlink.c', 'net/ipv4/ip_gre.c'], 'defaultStatus': 'affected'}] -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 20, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 19, 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': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '9831bc9ecb402957810c2045c663fbfe9b09e296', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '1697957eb0971d420dde42862b88eb43506a1105', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '47b5d3d506609b08b2e1f7c14f0b681a1953d572', 'versionType': 'git'}, {'status': 'affected', 'version': 'b57708add31494175be741ed3fd24023b50c3423', 'lessThan': '8165f7ff57d9667d2bb477ef6af83ede7fed4ad7', 'versionType': 'git'}], 'programFiles': ['include/net/rtnetlink.h', 'net/core/rtnetlink.c', 'net/ipv4/ip_gre.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '3.16'}, {'status': 'unaffected', 'version': '0', 'lessThan': '3.16', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.95', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.38', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.3', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['include/net/rtnetlink.h', 'net/core/rtnetlink.c', 'net/ipv4/ip_gre.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: net: ip_gre: require CAP_NET_ADMIN in the device netns for changelink A tunnel changelink() operates on at most two netns, dev_net(dev) and the tunnel link netns t->net. They differ once the device is created in or moved to a netns other than the one the request runs in. The rtnl changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a caller privileged there but not in t->net can rewrite a tunnel that lives in t->net. Add rtnl_dev_link_net_capable() next to rtnl_get_net_ns_capable() in net/core/rtnetlink.c. It requires CAP_NET_ADMIN in the link netns and is skipped when the link netns is dev_net(dev), where the rtnl path already checked it. The other patches in this series use the same helper. Gate ipgre_changelink() and erspan_changelink() with it, at the top of the op before any attribute is parsed, because the parsers update live tunnel fields first. ipgre_netlink_parms() sets t->collect_md before ip_tunnel_changelink() runs. Commit 8b484efd5cb4 ("ip6: vti: Use ip6_tnl.net in vti6_siocdevprivate().") added the same check on the ioctl path. This adds it on RTM_NEWLINK. Added Reference https://git.kernel.org/stable/c/1697957eb0971d420dde42862b88eb43506a1105 Added Reference https://git.kernel.org/stable/c/47b5d3d506609b08b2e1f7c14f0b681a1953d572 Added Reference https://git.kernel.org/stable/c/8165f7ff57d9667d2bb477ef6af83ede7fed4ad7 Added Reference https://git.kernel.org/stable/c/9831bc9ecb402957810c2045c663fbfe9b09e296
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.