CVE-2026-74630 — ipv6: prevent in6_dev_get() from resurrecting inet6_dev
In the Linux kernel, the following vulnerability has been resolved: ipv6: prevent in6_dev_get() from resurrecting inet6_dev in6_dev_get() reads dev->ip6_ptr under RCU and then unconditionally increments its refcount. Device teardown can clear the pointer and drop the last reference between these operations. The increment then resurrects an object whose RCU free has already been queued, so callers can use it after it is freed. Use refcount_inc_not_zero() and return NULL when the object has already reached zero. RCU keeps the memory accessible through the attempted reference acquisition, and a successful increment pins the object for the caller. An independent run on the exact unpatched 6f5156d7a31a (v7.2-rc3) kernel reproduced the invalid reference acquisition as UID 1000: refcount_t: addition on 0; use-after-free. ip6_mc_source+0xef4/0x17e0 It was followed by the corresponding reference underflow in ip6_mc_source(). The supplied trace from the same unpatched revision additionally shows the access after the RCU read-side section ends: BUG: KASAN: slab-use-after-free in mutex_lock+0x76/0xe0 Write of size 8 at addr ffff888015b50240 by task poc/1219 Bug found and triaged by OpenAI Security Research and validated by Trail of Bits.
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 0.1% (30-day exploitation probability)+0
- 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).
- 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 |
≥ 8814c4b533817df825485ff32ce6ac406c3a54d1 and < 785d908f8d21c8bc78b6fb2c2932ab662bf6918a≥ 8814c4b533817df825485ff32ce6ac406c3a54d1 and < aedcfefdb5b7ed7f8a6196a3e68a25bdbe51d2f8≥ 8814c4b533817df825485ff32ce6ac406c3a54d1 and < 145812b678de9f3b59780173be3c0d22ed60dd93≥ 8814c4b533817df825485ff32ce6ac406c3a54d1 and < cc5bd568f9b7683e60841b6fd02c10d64535bd6e≥ 8814c4b533817df825485ff32ce6ac406c3a54d1 and < 1c206d461c680c3151daa3c89fc26eaf5bf98a7f≥ 8814c4b533817df825485ff32ce6ac406c3a54d1 and < 680fbd7942185448eadb990a3d10a53eb946b702≥ 8814c4b533817df825485ff32ce6ac406c3a54d1 and < 14e812ab41df0cac033479da835ec9a5de633404≥ 8814c4b533817df825485ff32ce6ac406c3a54d1 and < 0e243671bc7b8eaf00f83dd2f4367436dc0cff98 and 1 moreversion 2.6.19 |
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 |
|---|---|---|---|---|---|
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | — | — | GitHub, Inc. via GitHub Security Advisories |
| 7.8 | CVSS 3.1 | High | — | — | Linux via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67) EPSS over time FIRST
Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 0.13%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- CVSS changed · 7.8
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× References added · Oct 14, 2026 – Oct 14, 2026
- 1× Official description updated · Oct 14, 2026 – Oct 14, 2026
References
10 on the record
- git.kernel.org/stable/c/145812b678de9f3b59780173be3c0d22ed60dd93
- git.kernel.org/stable/c/cc5bd568f9b7683e60841b6fd02c10d64535bd6e
- git.kernel.org/stable/c/14e812ab41df0cac033479da835ec9a5de633404
- git.kernel.org/stable/c/1c206d461c680c3151daa3c89fc26eaf5bf98a7f
- git.kernel.org/stable/c/0e243671bc7b8eaf00f83dd2f4367436dc0cff98
- git.kernel.org/stable/c/aedcfefdb5b7ed7f8a6196a3e68a25bdbe51d2f8
- github.com/advisories/GHSA-6g8v-5hwp-cmr2
- git.kernel.org/stable/c/785d908f8d21c8bc78b6fb2c2932ab662bf6918a
- nvd.nist.gov/vuln/detail/CVE-2026-74630
- git.kernel.org/stable/c/680fbd7942185448eadb990a3d10a53eb946b702
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 16h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 16h
- Unknown CVE-2026-98431 RDMA/uverbs: Fix mmap_lock/disassociation_lock circular dependency 1d
- Unknown CVE-2026-98430 RDMA/efa: Keep admin queues alive while IRQ is registered 1d
- Unknown CVE-2026-98429 RDMA/efa: Keep EQ resources alive while IRQ is registered 1d
- Unknown CVE-2026-98428 ALSA: usb: 6fire: Avoid embedded URBs 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-2026-74630 is "ipv6: prevent in6_dev_get() from resurrecting inet6_dev", 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 7.8 describes technical severity. EPSS 0.13% 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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