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

CVE-2026-98490: net: openvswitch: conntrack: fix helper UAF due to extensions realloc

Noroxi assessment

Priority: Monitor (action score 39/100)

  • 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: 0.61% (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.
  • Fixed version: Linux Linux 18866dc1f525f9ee4de7709529d1ae1af8d8e8be, 1a4151e6be57b098b7a5ebfbde58585e83200cdc, 5f23080a625dd7855ab91485c8d691a54a1979f0; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 18866dc1f525f9ee4de7709529d1ae1af8d8e8be, 1a4151e6be57b098b7a5ebfbde58585e83200cdc, 5f23080a625dd7855ab91485c8d691a54a1979f0; azl3 kernel 6.6.157.1-1 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: conntrack: fix helper UAF due to extensions realloc While calling the helpers, a raw pointer to the extensions area is wired into expectations list: -> nf_ct_helper() -> helper->help() -> nf_ct_expect_related_report() -> nf_ct_expect_insert() -> hlist_add_head_rcu(&exp->lnode, &master_help->expectations) In case the connection is not confirmed yet, more extensions can be added afterwards with *_ext_add() calls reallocating the extension space and leaving the now invalid pointer in the expectations list that is later accessed while removing the expectation. Make sure that helpers are called at the end after all the other extensions are already added. Note that the helper rejection now leaves the mark and labels set, but that's not different from how the NAT was handled before or how the mark and the labels were handled on confirmation failure. And there are no atomicity guarantees provided by the API anyway.

CriticalCVSS 9.8 · v3.1—No exploit Fix available
Published
Oct 18, 2026
Updated
Oct 30, 2026
EPSS
0.6% · 49th percentile
CWE
—

Report tools

JSON

Action score

39

Monitor

Low priority for now.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.6%

CNA vs NVD score

NVD
—
CNA · Linux
9.8
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.

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  • 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.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
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  • 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

    • 4.3affected
    • cae3a2627520c3795b54533c5328b77af3405dbe and later · before f53d13a286fb275bda0efdf445b8a1e4dfcb717baffected · git
    • cae3a2627520c3795b54533c5328b77af3405dbe and later · before 84d47a83b7b717576de0defab46b8823a22853b0affected · git
    • cae3a2627520c3795b54533c5328b77af3405dbe and later · before 9f308197395c1a524b736e401cbc8a2ed7d246c9affected · git
    • cae3a2627520c3795b54533c5328b77af3405dbe and later · before 18866dc1f525f9ee4de7709529d1ae1af8d8e8beaffected · git
    • cae3a2627520c3795b54533c5328b77af3405dbe and later · before afcf362625190c5260530b1d6c7daa98831f6b83affected · git
    • cae3a2627520c3795b54533c5328b77af3405dbe and later · before 5f23080a625dd7855ab91485c8d691a54a1979f0affected · git
    • cae3a2627520c3795b54533c5328b77af3405dbe and later · before e02a83bb0b7a203f6a22f55ad5f426765560f811affected · git
    • cae3a2627520c3795b54533c5328b77af3405dbe and later · before 1a4151e6be57b098b7a5ebfbde58585e83200cdcaffected · git
    • before 4.3not 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:12linux-6.12before 6.12.113-1~deb12u16.12.113-1~deb12u1
Debian:13linuxbefore 6.12.113-16.12.113-1
Debian:14linuxbefore 7.2.9-17.2.9-1

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-2026-98488Oct 18, 2026 · net: atl1e: fix soft lockup on out-of-range hw_next_to_clean read
    0Monitor
  • ← EarlierCVE-2026-98489Oct 18, 2026 · net: atl1c: fix soft lockup on out-of-range tpd_cons read
    0Monitor
  • Later →CVE-2026-98491Oct 18, 2026 · net: openvswitch: conntrack: avoid modifying shared unconfirmed ct entry
    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 Linux18866dc1f525f9ee4de7709529d1ae1af8d8e8beVendor (CNA)
Linux Linux1a4151e6be57b098b7a5ebfbde58585e83200cdcVendor (CNA)
Linux Linux5f23080a625dd7855ab91485c8d691a54a1979f0Vendor (CNA)
Linux Linux84d47a83b7b717576de0defab46b8823a22853b0Vendor (CNA)
Linux Linux9f308197395c1a524b736e401cbc8a2ed7d246c9Vendor (CNA)
Linux Linuxafcf362625190c5260530b1d6c7daa98831f6b83Vendor (CNA)
Linux Linuxe02a83bb0b7a203f6a22f55ad5f426765560f811Vendor (CNA)
Linux Linuxf53d13a286fb275bda0efdf445b8a1e4dfcb717bVendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
debian:linux6.12.113-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.113-1~deb12u1 · 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.

  1. Published
  2. Fix recordedsame day
  3. TodayOct 31, 2026+13 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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

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
high · data can be read
Integrity
high · 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
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

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

Change log

  1. CVSS— → 9.8
  2. Severity— → critical
  3. Exploit maturity— → none
  4. 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