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NVD / CVE Program· CNA Linux

CVE-2026-72021: ipvs: use parsed transport offset in SCTP state lookup

Noroxi assessment

Priority: Monitor (action score 32/100)

  • 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: 0.58% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: Linux Linux 247d055504dcc852e539b9f7f30d19f9741474bf, 290e9e8389b556efc603522e28bd1543846aa336, 2f75c0faa3361b28e36cc0512b3299e163e25789.

Low priority for now. Upgrade to Linux Linux 247d055504dcc852e539b9f7f30d19f9741474bf, 290e9e8389b556efc603522e28bd1543846aa336, 2f75c0faa3361b28e36cc0512b3299e163e25789 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: ipvs: use parsed transport offset in SCTP state lookup set_sctp_state() reads the SCTP chunk header again in order to drive the IPVS SCTP state table. For IPv6 it computes the offset with sizeof(struct ipv6hdr), while the surrounding IPVS code uses iph.len from ip_vs_fill_iph_skb(), where ipv6_find_hdr() has already skipped extension headers and found the real transport header. This makes the state machine read from the wrong offset for IPv6 SCTP packets that carry extension headers. For example, an INIT packet with an 8-byte destination options header can be scheduled correctly by sctp_conn_schedule(), but set_sctp_state() reads the first byte of the SCTP verification tag as a DATA chunk type. The connection then moves from NONE to ESTABLISHED instead of INIT1, gets the longer established timeout, and updates the active/inactive destination counters incorrectly. This happens even though the SCTP handshake has not completed. Use the parsed transport offset passed down from ip_vs_set_state() for the SCTP chunk-header lookup. For IPv4 and IPv6 packets without extension headers this preserves the existing offset.

HighCVSS 8.2 · v3.1—No exploit Fix available
Published
Aug 15, 2026
Updated
Oct 19, 2026
EPSS
0.5% · 48th percentile

Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
32 / 40 · 8.2 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
8.2
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-72021

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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

    • 2.6.34affected
    • 2906f66a5682e5670a5eefe991843689b8d8563f and later · before d2b8b1557ec07ea1bb5dddbceaf4dfe63d388e27affected · git
    • 2906f66a5682e5670a5eefe991843689b8d8563f and later · before 9f94573ab962a9e81954b755da016fa3cd2f5039affected · git
    • 2906f66a5682e5670a5eefe991843689b8d8563f and later · before 290e9e8389b556efc603522e28bd1543846aa336affected · git
    • 2906f66a5682e5670a5eefe991843689b8d8563f and later · before 9cb5ac594ca76d3a71803b23b74c835b0721e628affected · git
    • 2906f66a5682e5670a5eefe991843689b8d8563f and later · before a4a2d2e483d79cc2ad3a170674cf159644acf22baffected · git
    • 2906f66a5682e5670a5eefe991843689b8d8563f and later · before 247d055504dcc852e539b9f7f30d19f9741474bfaffected · git
    • 2906f66a5682e5670a5eefe991843689b8d8563f and later · before e5d0bb8871668f20de8f3c94b5ae3f372346bc6eaffected · git
    • 2906f66a5682e5670a5eefe991843689b8d8563f and later · before 2f75c0faa3361b28e36cc0512b3299e163e25789affected · git
    • before 2.6.34not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.180-16.1.180-1
Debian:13linuxbefore 6.12.100-16.12.100-1
Debian:14linuxbefore 7.1.5-17.1.5-1

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-2026-72019Aug 15, 2026 · macsec: don't read an unset MAC header in macsec_encrypt()
    29Monitor
  • ← EarlierCVE-2026-72020Aug 15, 2026 · ipvs: reset full ip_vs_seq structs in ip_vs_conn_new
    39Monitor
  • Later →CVE-2026-72024Aug 15, 2026 · mac802154: remove interfaces with RCU list deletion
    31Monitor

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 Linux247d055504dcc852e539b9f7f30d19f9741474bfVendor (CNA)
Linux Linux290e9e8389b556efc603522e28bd1543846aa336Vendor (CNA)
Linux Linux2f75c0faa3361b28e36cc0512b3299e163e25789Vendor (CNA)
Linux Linux9cb5ac594ca76d3a71803b23b74c835b0721e628Vendor (CNA)
Linux Linux9f94573ab962a9e81954b755da016fa3cd2f5039Vendor (CNA)
Linux Linuxa4a2d2e483d79cc2ad3a170674cf159644acf22bVendor (CNA)
Linux Linuxd2b8b1557ec07ea1bb5dddbceaf4dfe63d388e27Vendor (CNA)
Linux Linuxe5d0bb8871668f20de8f3c94b5ae3f372346bc6eVendor (CNA)
debian:linux6.1.180-1 · Debian:12Package 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.

No dated events beyond publication.

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.

  • CVE-2026-684770 days apartipvs: fix more places with wrong ipv6 transport offsets
    39Monitor
  • CVE-2026-720650 days apartnet: mana: Validate the packet length reported by the NIC
    39Monitor
  • CVE-2026-681545 days apartlibceph: reject zero bucket types in crush_decode
    39Monitor
  • CVE-2026-9999961 days apartipv4: validate checksum_start before completing checksum
    37Monitor
  • CVE-2026-684700 days apartwifi: mac80211: validate extension-frame layout before RX
    35Monitor
  • CVE-2026-684542 days apartKVM: s390: pci: Fix handling of AIF enable without AISB
    35Monitor

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

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
low · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
Low
Availability impact
High

Weakness class (CWE)

CWE-20 · Improper Input Validation

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

nvd-secondary

Attack context

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

Change log

  1. SSVC exploitation— → 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