CVE-2026-74550 — net: do not send ICMP/NDISC Redirects when peer allocation fails
In 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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.5% (30-day exploitation probability)+6
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux | ≥ 92d8682926342d2b6aa5b2ecc02221e00e1573a0 and < c0adf8b4247bcc5a145a25c1929006eb392580bb≥ 92d8682926342d2b6aa5b2ecc02221e00e1573a0 and < f5ecaa7ea7686fa7ecdb6affc9d3a9a42e4524b1≥ 92d8682926342d2b6aa5b2ecc02221e00e1573a0 and < 21666f7af49a90ef44d474916b8ef4402dfd74f5≥ 92d8682926342d2b6aa5b2ecc02221e00e1573a0 and < 5ec5f00fc606a6df8434948c4552b3cb1176595d≥ 92d8682926342d2b6aa5b2ecc02221e00e1573a0 and < 828f6670d110ff2bf44c743037b38badc315704c≥ 92d8682926342d2b6aa5b2ecc02221e00e1573a0 and < dbc3791e3b2472e1ccc08947e0f83b443470ff4fversion 2.6.39 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.5 | CVSS 3.1 | High | 3.9 | 3.6 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database |
| 7.5 | CVSS 3.1 | High | — | — | Linux via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67) Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- CVSS changed · 7.5
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
6 on the record
- git.kernel.org/stable/c/828f6670d110ff2bf44c743037b38badc315704c
- git.kernel.org/stable/c/21666f7af49a90ef44d474916b8ef4402dfd74f5
- git.kernel.org/stable/c/c0adf8b4247bcc5a145a25c1929006eb392580bb
- git.kernel.org/stable/c/5ec5f00fc606a6df8434948c4552b3cb1176595d
- git.kernel.org/stable/c/f5ecaa7ea7686fa7ecdb6affc9d3a9a42e4524b1
- git.kernel.org/stable/c/dbc3791e3b2472e1ccc08947e0f83b443470ff4f
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 20h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 20h
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-74550 is "net: do not send ICMP/NDISC Redirects when peer allocation fails", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.5 describes technical severity. EPSS 0.48% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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