ipv6: do not let ipv6_find_hdr() return an offset past the packet end
Assessment
- Severity
- Moderate
- CVSS base score
- 5.6CVSS:3.1/
AV:L/ AC:L/ PR:H/ UI:N/ S:U/ C:L/ I:L/ A:H - Impact
- Not stated
- EPSS, next 30 days
- Not scored yet
- Public exploit code
- No Nuclei template lists it
- Exploitability
- Not assessed
- Publicly disclosed
- No
- Customer action
- Required: apply the update
- Component
- Mariner
- Weakness
- —
- Issued by
- Linux
- Published
- 20 Oct 2026 · October 2026
- Last revised
- 24 Oct 2026Information published.
- Attack vector
- LocalAV:L
- Attack complexity
- LowAC:L
- Privileges required
- HighPR:H
- User interaction
- NoneUI:N
- Scope
- UnchangedS:U
- Confidentiality
- LowC:L
- Integrity
- LowI:L
- Availability
- HighA:H
Updates that fix it
0 KBsNo KB listed
MSRC lists no downloadable update, which usually means a service-side fix or a release-notes update. Check the MSRC advisory.
Affected products
1 affected product
- azl3 kernel 6.6.157.1-1 on Azure Linux 3.0
What changed
First observed 20 Oct 2026- 25 Oct 2026 · 07:41:18 UTC Last revised21 Oct 2026 18:38 UTC → 24 Oct 2026 14:46 UTC
- 23 Oct 2026 · 09:33:49 UTC Public exploit codeUnknown: exploit-code evidence is incomplete or retained → No Nuclei template listed
- 23 Oct 2026 · 09:33:49 UTC CISA KEVUnknown: catalog evidence is incomplete or retained → Not listed in the collected catalog
- 23 Oct 2026 · 09:33:49 UTC Source coverage: public-exploit-codeIncomplete → Current
- 23 Oct 2026 · 09:33:49 UTC Source coverage: first-epssIncomplete → Current
- 23 Oct 2026 · 09:33:49 UTC Source coverage: cisa-kevIncomplete → Current
- 23 Oct 2026 · 09:33:49 UTC Source coverage: msrc-cvrfIncomplete → Current
- 23 Oct 2026 · 08:31:50 UTC Public exploit codeNo Nuclei template listed → Unknown: exploit-code evidence is incomplete or retained
- 23 Oct 2026 · 08:31:50 UTC CISA KEVNot listed in the collected catalog → Unknown: catalog evidence is incomplete or retained
- 23 Oct 2026 · 08:31:50 UTC Source coverage: public-exploit-codeCurrent → Incomplete
- 23 Oct 2026 · 08:31:50 UTC Source coverage: first-epssCurrent → Incomplete
- 23 Oct 2026 · 08:31:50 UTC Source coverage: cisa-kevCurrent → Incomplete
Show 2 more recent changes
- 23 Oct 2026 · 08:31:50 UTCSource coverage: msrc-cvrf Current → Incomplete
- 21 Oct 2026 · 20:45:25 UTCLast revised 20 Oct 2026 01:02 UTC → 21 Oct 2026 18:38 UTC
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Explore global source statements, affected packages and advisory history for CVE-2026-98532. The catalog has a separate collection scope from Microsoft release records.
Collected exploitation and prediction evidence
Risk source coverageCISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.
No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.
cve-program · CVE-2026-98532
Publishedipv6: do not let ipv6_find_hdr() return an offset past the packet end
In the Linux kernel, the following vulnerability has been resolved: ipv6: do not let ipv6_find_hdr() return an offset past the packet end ipv6_find_hdr() walks the extension header chain, skipping each header by the length that header itself declares. ipv6_optlen() returns up to 2048, and the skip is never checked against skb->len, so the offset stored in *offset can point past the end of the packet. openvswitch installs that offset as the transport header, and update_ipv6_checksum() then reads and writes the transport checksum field out of bounds: BUG: KASAN: slab-use-after-free in inet_proto_csum_replace16+0x445/0x470 Read of size 2 at addr ffff88810b754b06 by task ovs_ipv6_oob/629 CPU: 4 UID: 1000 PID: 629 Comm: ovs_ipv6_oob Tainted: G N 7.3.0-rc3+ #348 Call Trace: inet_proto_csum_replace16+0x445/0x470 set_ipv6_addr+0x3dd/0x460 do_execute_actions+0x6a3d/0x7c40 ovs_execute_actions+0xfd/0x480 ovs_packet_cmd_execute+0xc38/0xf20 genl_rcv_msg+0x59e/0x870 netlink_rcv_skb+0x18b/0x450 genl_rcv+0x2d/0x40 netlink_unicast+0x6bc/0xa20 The buggy address belongs to the object at ffff88810b754980 which belongs to the cache skbuff_small_head of size 704 The buggy address is located 390 bytes inside of freed 704-byte region [ffff88810b754980, ffff88810b754c40) Other callers use that offset too, so bound it here rather than in one caller. Reject a header whose declared length does not fit in the packet. ipv6_find_hdr() already fails with -EBADMSG on a malformed chain, so this adds no new failure mode.
- Source published
- 18 Oct 2026 15:17:50 UTC
- Source modified
- 24 Oct 2026 14:09:19 UTC
- Observed here
- 24 Oct 2026 16:17:04 UTC
- Source terms
- CVE Program Terms of Use
Original source record · Cite this exact observation · Complete original publisher JSON
This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.
CVSS 3.1 · 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H