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CVE.org (no NVD analysis yet)· CNA Linux

CVE-2026-99088: net: openvswitch: validate transport header presence in set_ipv6_addr

Noroxi assessment

Priority: Monitor (action score 0/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.17% (FIRST EPSS).
  • Fixed version: Linux Linux 1efa6842e94aa70237446b31fbe2bc16586809c3, 2594795fd832f0253826d64ff8976b8ff5fbfe9f, 3c6a4b11330fe424557538a98fca9f0a4c5bf313; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 Release Notes.

Low priority for now. Upgrade to Linux Linux 1efa6842e94aa70237446b31fbe2bc16586809c3, 2594795fd832f0253826d64ff8976b8ff5fbfe9f, 3c6a4b11330fe424557538a98fca9f0a4c5bf313; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 Release Notes or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: validate transport header presence in set_ipv6_addr When executing IPv6 address rewrite actions on IPv6 fragments, set_ipv6_addr() calls update_ipv6_checksum(). If parse_ipv6hdr() processes a non-first IPv6 fragment, it sets key->ip.proto to NEXTHDR_FRAGMENT and returns early without calling skb_set_transport_header(). update_ipv6_checksum() unconditionally evaluates skb_transport_offset() on entry before checking l4_proto. Because skb->transport_header is uninitialized, this triggers a warning under CONFIG_DEBUG_NET=y although it is completely harmless. Fix this by returning early in update_ipv6_checksum() if l4_proto is NEXTHDR_FRAGMENT. This avoids reading the uninitialized transport offset for fragments while preserving the debug warning for any other protocol where the transport header is unexpectedly missing. See the syzbot trace: !skb_transport_header_was_set(skb) WARNING: ./include/linux/skbuff.h:3075 at skb_transport_header include/linux/skbuff.h:3075 [inline], CPU#1: syz-executor463/5635 WARNING: ./include/linux/skbuff.h:3075 at skb_transport_offset include/linux/skbuff.h:3250 [inline], CPU#1: syz-executor463/5635 WARNING: ./include/linux/skbuff.h:3075 at update_ipv6_checksum net/openvswitch/actions.c:361 [inline], CPU#1: syz-executor463/5635 WARNING: ./include/linux/skbuff.h:3075 at set_ipv6_addr+0x462/0x660 net/openvswitch/actions.c:399, CPU#1: syz-executor463/5635 [...] RIP: 0010:skb_transport_header include/linux/skbuff.h:3075 [inline] RIP: 0010:skb_transport_offset include/linux/skbuff.h:3250 [inline] RIP: 0010:update_ipv6_checksum net/openvswitch/actions.c:361 [inline] RIP: 0010:set_ipv6_addr+0x462/0x660 net/openvswitch/actions.c:399 [...] Call Trace: <TASK> set_ipv6 net/openvswitch/actions.c:531 [inline] do_execute_actions+0x557e/0x8600 net/openvswitch/actions.c:1366 ovs_execute_actions+0xde/0x520 net/openvswitch/actions.c:1592 ovs_packet_cmd_execute+0xb4f/0xf10 net/openvswitch/datapath.c:705 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114 genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2572 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800

—No exploit Fix available
Published
Oct 26, 2026
Updated
Oct 30, 2026
EPSS
0.1% · 6th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 3.8affected
    • 3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b and later · before 1efa6842e94aa70237446b31fbe2bc16586809c3affected · git
    • 3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b and later · before ad4258db21e801a7aae614afca89a2e39283080daffected · git
    • 3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b and later · before 54cb98ed23866205926298621e04169f50665b59affected · git
    • 3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b and later · before b7b80d204abdc258006f9e17c92b363ab13bb599affected · git
    • 3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b and later · before 6774af7cd17be8f0d0f70de3a749d381b4f2e9daaffected · git
    • 3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b and later · before 2594795fd832f0253826d64ff8976b8ff5fbfe9faffected · git
    • 3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b and later · before 6b8897ba0733f88f0360ea48a970f373f9142de0affected · git
    • 3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b and later · before 3c6a4b11330fe424557538a98fca9f0a4c5bf313affected · git
    • before 3.8not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:13linuxbefore 6.12.113-16.12.113-1
Debian:14linuxbefore 7.2.11-17.2.11-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-99086Oct 23, 2026 · dm-integrity: validate the superblock on resume
    0Monitor
  • ← EarlierCVE-2026-99087Oct 23, 2026 · dm-integrity: fix NULL pointer dereference when the 'R' flag is used
    0Monitor
  • Later →CVE-2026-99089Oct 26, 2026 · ASoC: samsung: i2s: enable op_clk in probe to balance runtime PM
    0Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux1efa6842e94aa70237446b31fbe2bc16586809c3Vendor (CNA)
Linux Linux2594795fd832f0253826d64ff8976b8ff5fbfe9fVendor (CNA)
Linux Linux3c6a4b11330fe424557538a98fca9f0a4c5bf313Vendor (CNA)
Linux Linux54cb98ed23866205926298621e04169f50665b59Vendor (CNA)
Linux Linux6774af7cd17be8f0d0f70de3a749d381b4f2e9daVendor (CNA)
Linux Linux6b8897ba0733f88f0360ea48a970f373f9142de0Vendor (CNA)
Linux Linuxad4258db21e801a7aae614afca89a2e39283080dVendor (CNA)
Linux Linuxb7b80d204abdc258006f9e17c92b363ab13bb599Vendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 kernel 6.6.159.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
debian:linux6.12.113-1 · Debian:13Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. Fix recordedsame day
  3. TodayNov 5, 2026+9 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Exploit maturity— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records