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

CVE-2026-98555: llc: fix skb UAF and leaks on llc_mac_hdr_init() failure

Noroxi assessment

Priority: Monitor (action score 30/100)

  • 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: 0.31% (FIRST EPSS).
  • Someone on the same network segment can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: Linux Linux 060f827aa3dc47939ee306da715cd6700d129616, 41dcae82bece9f106b4dff0ee777bba8d157c8a8, 72f9dd522f8d6c5a00be9695c7bb74631eb5069e; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.159.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 060f827aa3dc47939ee306da715cd6700d129616, 41dcae82bece9f106b4dff0ee777bba8d157c8a8, 72f9dd522f8d6c5a00be9695c7bb74631eb5069e; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.159.1-1 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: llc: fix skb UAF and leaks on llc_mac_hdr_init() failure In llc_conn_ac_resend_i_xxx_x_set_0_or_send_rr(), if llc_mac_hdr_init() fails, kfree_skb(skb) is called instead of kfree_skb(nskb). This leaks the newly allocated nskb, reads from the freed skb via LLC_I_GET_NR(pdu), and double-frees skb when llc_conn_state_process() drops its reference. In llc_sap_action_send_xid_r() and llc_sap_action_send_test_r(), nskb is leaked if llc_mac_hdr_init() returns an error. Free nskb in all three error paths.

HighCVSS 7.5 · v3.1—No exploit Fix available
Published
Oct 18, 2026
Updated
Oct 24, 2026
EPSS
0.3% · 23th percentile
CWE
—

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CNA vs NVD score

NVD
—
CNA · Linux
7.5
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

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When you'll hear from us

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  • 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

    • 2.6.12affected
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before fec0fe6838a7f45175667701fb51abb23a6ffb1eaffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before b859ba18b5a1067f71db5618c6a4a70d55fa308baffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 8b855b645841b5a04e20339a22bb6d593c9b790daffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before d360b31f1a3666579422872aa7d1a751e20b76f9affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 060f827aa3dc47939ee306da715cd6700d129616affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 41dcae82bece9f106b4dff0ee777bba8d157c8a8affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before cb3528ad8bb46fa6252f5d14ced7febddc18515daffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 72f9dd522f8d6c5a00be9695c7bb74631eb5069eaffected · git
    • before 2.6.12not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.190-16.1.190-1
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-2026-98553Oct 18, 2026 · autofs: fix sbi->pipe file reference leak in autofs_kill_sb()
    0Monitor
  • ← EarlierCVE-2026-98554Oct 18, 2026 · vlan: ensure sufficient headroom in vlan_dev_hard_header()
    0Monitor
  • Later →CVE-2026-98556Oct 18, 2026 · gve: DQO: reject TSO packets with an out of range MSS
    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 Linux060f827aa3dc47939ee306da715cd6700d129616Vendor (CNA)
Linux Linux41dcae82bece9f106b4dff0ee777bba8d157c8a8Vendor (CNA)
Linux Linux72f9dd522f8d6c5a00be9695c7bb74631eb5069eVendor (CNA)
Linux Linux8b855b645841b5a04e20339a22bb6d593c9b790dVendor (CNA)
Linux Linuxb859ba18b5a1067f71db5618c6a4a70d55fa308bVendor (CNA)
Linux Linuxcb3528ad8bb46fa6252f5d14ced7febddc18515dVendor (CNA)
Linux Linuxd360b31f1a3666579422872aa7d1a751e20b76f9Vendor (CNA)
Linux Linuxfec0fe6838a7f45175667701fb51abb23a6ffb1eVendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.06.6.159.1-1 · Release NotesMicrosoft (MSRC)
debian:linux6.1.190-1 · Debian:12Package 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. TodayNov 7, 2026+19 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

  • Someone on the same network segment can trigger it.
  • No account or password is required.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

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
Adjacent
Attack complexity
High
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:A/AC:H/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— → 7.5
  2. Severity— → high
  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