CVE Intelligence
High Denial of service

CVE-2024-35969 — ipv6: fix race condition between ipv6_get_ifaddr and ipv6_del_addr

In the Linux kernel, the following vulnerability has been resolved: ipv6: fix race condition between ipv6_get_ifaddr and ipv6_del_addr Although ipv6_get_ifaddr walks inet6_addr_lst under the RCU lock, it still means hlist_for_each_entry_rcu can return an item that got removed from the list. The memory itself of such item is not freed thanks to RCU but nothing guarantees the actual content of the memory is sane. In particular, the reference count can be zero. This can happen if ipv6_del_addr is called in parallel. ipv6_del_addr removes the entry from inet6_addr_lst (hlist_del_init_rcu(&ifp->addr_lst)) and drops all references (__in6_ifa_put(ifp) + in6_ifa_put(ifp)). With bad enough timing, this can happen: 1. In ipv6_get_ifaddr, hlist_for_each_entry_rcu returns an entry. 2. Then, the whole ipv6_del_addr is executed for the given entry. The reference count drops to zero and kfree_rcu is scheduled. 3. ipv6_get_ifaddr continues and tries to increments the reference count (in6_ifa_hold). 4. The rcu is unlocked and the entry is freed. 5. The freed entry is returned. Prevent increasing of the reference count in such case. The name in6_ifa_hold_safe is chosen to mimic the existing fib6_info_hold_safe. [ 41.506330] refcount_t: addition on 0; use-after-free. [ 41.506760] WARNING: CPU: 0 PID: 595 at lib/refcount.c:25 refcount_warn_saturate+0xa5/0x130 [ 41.507413] Modules linked in: veth bridge stp llc [ 41.507821] CPU: 0 PID: 595 Comm: python3 Not tainted 6.9.0-rc2.main-00208-g49563be82afa #14 [ 41.508479] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) [ 41.509163] RIP: 0010:refcount_warn_saturate+0xa5/0x130 [ 41.509586] Code: ad ff 90 0f 0b 90 90 c3 cc cc cc cc 80 3d c0 30 ad 01 00 75 a0 c6 05 b7 30 ad 01 01 90 48 c7 c7 38 cc 7a 8c e8 cc 18 ad ff 90 <0f> 0b 90 90 c3 cc cc cc cc 80 3d 98 30 ad 01 00 0f 85 75 ff ff ff [ 41.510956] RSP: 0018:ffffbda3c026baf0 EFLAGS: 00010282 [ 41.511368] RAX: 0000000000000000 RBX: ffff9e9c46914800 RCX: 0000000000000000 [ 41.511910] RDX: ffff9e9c7ec29c00 RSI: ffff9e9c7ec1c900 RDI: ffff9e9c7ec1c900 [ 41.512445] RBP: ffff9e9c43660c9c R08: 0000000000009ffb R09: 00000000ffffdfff [ 41.512998] R10: 00000000ffffdfff R11: ffffffff8ca58a40 R12: ffff9e9c4339a000 [ 41.513534] R13: 0000000000000001 R14: ffff9e9c438a0000 R15: ffffbda3c026bb48 [ 41.514086] FS: 00007fbc4cda1740(0000) GS:ffff9e9c7ec00000(0000) knlGS:0000000000000000 [ 41.514726] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 41.515176] CR2: 000056233b337d88 CR3: 000000000376e006 CR4: 0000000000370ef0 [ 41.515713] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 41.516252] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 41.516799] Call Trace: [ 41.517037] <TASK> [ 41.517249] ? __warn+0x7b/0x120 [ 41.517535] ? refcount_warn_saturate+0xa5/0x130 [ 41.517923] ? report_bug+0x164/0x190 [ 41.518240] ? handle_bug+0x3d/0x70 [ 41.518541] ? exc_invalid_op+0x17/0x70 [ 41.520972] ? asm_exc_invalid_op+0x1a/0x20 [ 41.521325] ? refcount_warn_saturate+0xa5/0x130 [ 41.521708] ipv6_get_ifaddr+0xda/0xe0 [ 41.522035] inet6_rtm_getaddr+0x342/0x3f0 [ 41.522376] ? __pfx_inet6_rtm_getaddr+0x10/0x10 [ 41.522758] rtnetlink_rcv_msg+0x334/0x3d0 [ 41.523102] ? netlink_unicast+0x30f/0x390 [ 41.523445] ? __pfx_rtnetlink_rcv_msg+0x10/0x10 [ 41.523832] netlink_rcv_skb+0x53/0x100 [ 41.524157] netlink_unicast+0x23b/0x390 [ 41.524484] netlink_sendmsg+0x1f2/0x440 [ 41.524826] __sys_sendto+0x1d8/0x1f0 [ 41.525145] __x64_sys_sendto+0x1f/0x30 [ 41.525467] do_syscall_64+0xa5/0x1b0 [ 41.525794] entry_SYSCALL_64_after_hwframe+0x72/0x7a [ 41.526213] RIP: 0033:0x7fbc4cfcea9a [ 41.526528] Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 15 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 7e c3 0f 1f 44 00 00 41 54 48 83 ec 30 44 89 [ 41.527942] RSP: 002b:00007f ---truncated---

Published May 20, 2024 · Updated Oct 14, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: Linux

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.4% (30-day exploitation probability)+4
  • 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.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.38%
ahead of 30% of scored CVEs · Oct 14, 2026
Affects
Debian
Debian Linux and 2 more
CVSS base
8.8
High · 5 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)

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.

  1. Identify exposed assets running the affected vendor/product/version combinations (Debian Debian Linux, Linux Linux, Linux Linux Kernel).
  2. Apply the fixed version or the patch documented under Remediation.
  3. Search available logs for exploit probes matching the vulnerability class (denial of service), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Debian Debian Linux version 10.0 Vulnerable NIST National Vulnerability Database
Linux Linux version 2.6.35≥ 5c578aedcb21d79eeb4e9cf04ca5b276ac82614c and < 7633c4da919ad51164acbf1aa322cc1a3ead6129≥ 5c578aedcb21d79eeb4e9cf04ca5b276ac82614c and < 6cdb20c342cd0193d3e956e3d83981d0f438bb83≥ 5c578aedcb21d79eeb4e9cf04ca5b276ac82614c and < 01b11a0566670612bd464a932e5ac2eae53d8652≥ 5c578aedcb21d79eeb4e9cf04ca5b276ac82614c and < de76ae9ea1a6cf9e77fcec4f2df2904e26c23ceb≥ 5c578aedcb21d79eeb4e9cf04ca5b276ac82614c and < 4b19e9507c275de0cfe61c24db69179dc52cf9fb≥ 5c578aedcb21d79eeb4e9cf04ca5b276ac82614c and < 3fb02ec57ead2891a2306af8c51a306bc5945e70≥ 5c578aedcb21d79eeb4e9cf04ca5b276ac82614c and < cca606e14264098cba65efa82790825dbf69e903
and 1 more ≥ 5c578aedcb21d79eeb4e9cf04ca5b276ac82614c and < b4b3b69a19016d4e7fbdbd1dbcc184915eb862e1
Vulnerable CVE Program (cve.org) e CISA ADP
Linux Linux Kernel version 6.9-rc3version 6.9-rc2version 6.9-rc1≥ 6.7 and < 6.8.7≥ 6.2 and < 6.6.28≥ 5.16 and < 6.1.87≥ 5.11 and < 5.15.156≥ 5.5 and < 5.10.216
and 2 more ≥ 4.20 and < 5.4.275≥ 2.6.35 and < 4.19.313
Vulnerable NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Adjacent
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
8.8 CVSS 3.1 High 2.8 5.9 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database
8.8 CVSS 3.1 High — — Linux via CVE Program (cve.org) e CISA ADP
5.5 CVSS 3.1 Medium 1.8 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database
5.5 CVSS 3.1 Medium — — GitHub, Inc. via GitHub Security Advisories
5.5 CVSS 3.1 Medium — — CISA-ADP via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67)
Scoring entities (NIST, CNA, ADP) score independently; each score is shown with its origin. For prioritization we use 8.8 (416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-770 · Allocation of Resources Without Limits or Throttling

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Track CPU/memory spikes and availability drops correlated with request patterns.
resource metrics

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · linux/linux
    Oct 14, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 14, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 14, 2026
  • Fix documented
    Oct 14, 2026 · NIST National Vulnerability Database
  • Affected products added · linux/linux kernel, debian/debian linux
    Oct 14, 2026 · NIST National Vulnerability Database
  • CVSS changed · 8.8
    Oct 14, 2026 · NIST National Vulnerability Database
  • Source status changed · → Modified
    Oct 14, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 14, 2026 · Alertas do Telegram
  • 2024
  • CVE published
    May 20, 2024 · Linux

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 14, 2026 – Oct 14, 2026
  • 1× Official description updated · Oct 14, 2026 – Oct 14, 2026

References

14 on the record

Elsewhere on this site

Debian
every CVE for this vendor
Denial of service
same class
CWE-770
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-99999 ipv4: validate checksum_start before completing checksum 11h
  • CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 11h
  • CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
  • CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
  • CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
  • 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 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-2024-35969 is "ipv6: fix race condition between ipv6_get_ifaddr and ipv6_del_addr", rated High. It affects Debian Linux (Debian); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.8 describes technical severity. EPSS 0.38% 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.

Comments

Moderated technical discussion. Read the community guidelines.

No comments yet.

Sign in or create an account to comment and suggest corrections.