CVE-2026-46120: ip6_gre: Use cached t->net in ip6erspan_changelink().
Vulnerability summary
CVE-2026-46120 is a high (CVSS 7.8) Use After Free vulnerability in linux. EPSS estimates a 0.13% chance of exploitation in the next 30 days, higher than 2.4% of scored vulnerabilities.
Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 206 · Related 198Showing 100 of 206.
Timeline
- 28-05-2026PublishedVulnerability first disclosed.
- 19-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: ip6_gre: Use cached t->net in ip6erspan_changelink(). After commit 5e72ce3e3980 ("net: ipv6: Use link netns in newlink() of rtnl_link_ops"), ip6erspan_newlink() correctly resolves the per-netns ip6gre hash via link_net. ip6erspan_changelink() was not converted in that series and still uses dev_net(dev), which diverges from the device's creation netns after IFLA_NET_NS_FD migration. This re-inserts the tunnel into the wrong per-netns hash. The original netns keeps a stale entry. When that netns is later destroyed, ip6gre_exit_rtnl_net() walks the stale entry, producing a slab-use-after-free reported by KASAN, followed by a kernel BUG at net/core/dev.c (LIST_POISON1) in unregister_netdevice_many_notify(). Reachable from an unprivileged user namespace (unshare --user --map-root-user --net). ip6gre_changelink() earlier in the same file already uses the cached t->net; only ip6erspan_changelink() has the wrong shape.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- NVDNIST7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.13%
Chance of exploitation in the next 30 days
Percentile
2%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.13% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu162 products
- linuxAll versions (No fix recorded) | < 5.15.0-186.196 | < 6.8.0-136.136 | < 7.0.0-28.28
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 5.15.0-1112.119 | < 6.8.0-1061.64 | < 7.0.0-1009.9
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 2d665034f239412927b1e71329f20f001c92da09, < 7bd0f2b162b426b343a114e1b329f0d8d14fdc6e | ≥ 2d665034f239412927b1e71329f20f001c92da09, < 01b71ff2857d3598337de11e7840a8e3ff21553c | ≥ 2d665034f239412927b1e71329f20f001c92da09, < 0fcf6731706f73494245a9c0d64f93bebf95bb51 | ≥ 2d665034f239412927b1e71329f20f001c92da09, < eca62bb0569de4d43a4dac06a2092a9d4ca1d702 | ≥ 2d665034f239412927b1e71329f20f001c92da09, < 311fdd26eb4443d43b909cc67a10f3a5fd1b21b2 | ≥ 2d665034f239412927b1e71329f20f001c92da09, < e70cfb40c3a99b232cd42c6a6a10f0d8e039dc82 | ≥ 2d665034f239412927b1e71329f20f001c92da09, < cf7fc624329e76c6394653d12353e1d033adea91 | ≥ 2d665034f239412927b1e71329f20f001c92da09, < 1d324c2f43f70c965f25c58cc3611c779adbe47e | c6d72628352c949629af619b77b042e0fb5245e7 | ≥ 4.16.12, < 4.17 | 4.17
- linux_kernel≥ 4.16.12, < 4.17 | ≥ 4.17.1, < 5.10.258 | ≥ 5.11, < 5.15.209 | ≥ 5.16, < 6.1.175 | ≥ 6.2, < 6.6.140 | ≥ 6.7, < 6.12.88 | ≥ 6.13, < 6.18.30 | ≥ 6.19, < 7.0.7 | 4.17 | 4.17:rc7 | 7.1:rc1 | 7.1:rc2
Debian1 product
- linux< 6.1.176-1 | < 6.12.88-1 | < 7.0.7-1
3 vendors · 165 products
