GHSA-9CCH-CJJM-3M2C
Vulnerability from github – Published: 2026-08-15 15:30 – Updated: 2026-08-19 18:32In the Linux kernel, the following vulnerability has been resolved:
net: do not send ICMP/NDISC Redirects when peer allocation fails
When inet_getpeer_v4() or inet_getpeer_v6() fails to allocate a peer entry under memory pressure or tree size caps, redirect handlers previously fell back to sending un-rate-limited ICMP/NDISC Redirect messages.
In IPv4, ip_rt_send_redirect() called icmp_send() directly when peer == NULL. In IPv6, ip6_forward() and ndisc_send_redirect() passed a NULL peer into inet_peer_xrlim_allow(), which returned true when peer == NULL.
Because ICMP/NDISC Redirects are not part of the default global rate limit mask (sysctl_icmp_ratemask), sending redirects when peer == NULL creates an un-rate-limited ICMP packet storm.
Fix this by failing closed in ip_rt_send_redirect(), ip6_forward(), and ndisc_send_redirect() when peer is NULL.
{
"affected": [],
"aliases": [
"CVE-2026-74550"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-15T13:18:00Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: do not send ICMP/NDISC Redirects when peer allocation fails\n\nWhen inet_getpeer_v4() or inet_getpeer_v6() fails to allocate a peer entry\nunder memory pressure or tree size caps, redirect handlers previously fell\nback to sending un-rate-limited ICMP/NDISC Redirect messages.\n\nIn IPv4, ip_rt_send_redirect() called icmp_send() directly when peer == NULL.\nIn IPv6, ip6_forward() and ndisc_send_redirect() passed a NULL peer into\ninet_peer_xrlim_allow(), which returned true when peer == NULL.\n\nBecause ICMP/NDISC Redirects are not part of the default global rate limit\nmask (sysctl_icmp_ratemask), sending redirects when peer == NULL creates\nan un-rate-limited ICMP packet storm.\n\nFix this by failing closed in ip_rt_send_redirect(), ip6_forward(), and\nndisc_send_redirect() when peer is NULL.",
"id": "GHSA-9cch-cjjm-3m2c",
"modified": "2026-08-19T18:32:31Z",
"published": "2026-08-15T15:30:36Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74550"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/21666f7af49a90ef44d474916b8ef4402dfd74f5"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5ec5f00fc606a6df8434948c4552b3cb1176595d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/828f6670d110ff2bf44c743037b38badc315704c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c0adf8b4247bcc5a145a25c1929006eb392580bb"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/dbc3791e3b2472e1ccc08947e0f83b443470ff4f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f5ecaa7ea7686fa7ecdb6affc9d3a9a42e4524b1"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
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