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NVD / CVE Program· CNA Linux

CVE-2026-89789: gtp: add synchronize_net() in gtp_newlink() error path to prevent use-after-free

Noroxi assessment

Priority: Monitor (action score 31/100)

  • 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: 0.16% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 3ca3da5c305caa873ddb81e8c6b118143f6dd3d1, 6f815c2fb6ab20385f81c353cdad0ea3b88132af, 7677eb2cbf2cc7446de474c01a6b06277c0051e5; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1.

Low priority for now. Upgrade to Linux Linux 3ca3da5c305caa873ddb81e8c6b118143f6dd3d1, 6f815c2fb6ab20385f81c353cdad0ea3b88132af, 7677eb2cbf2cc7446de474c01a6b06277c0051e5; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1 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: gtp: add synchronize_net() in gtp_newlink() error path to prevent use-after-free gtp_newlink()'s error path frees tid_hash and addr_hash without waiting for an RCU grace period after clearing sk_user_data. A concurrent gtp_encap_recv() in softirq may still hold the gtp_dev pointer obtained via rcu_dereference_sk_user_data() and access the freed memory. BUG: KASAN: slab-use-after-free in gtp0_pdp_find+0x1f6/0x200 (gtp.c:152) Call Trace: <IRQ> gtp0_pdp_find+0x1f6/0x200 gtp_encap_recv+0x527/0x24b0 udp_queue_rcv_one_skb+0x75f/0xc10 Add synchronize_net() before the kfree calls in out_hashtable, which covers all error paths from both gtp_encap_enable() and gtp_create_sockets().

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Sep 16, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 5th percentile
CWE
—

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CNA vs NVD score

NVD
—
CNA · Linux
7.8
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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  • A fix has been released

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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

    • 4.7affected
    • 459aa660eb1d8ce67080da1983bb81d716aa5a69 and later · before fcafb2b1430824bae4258c01a439ec97ca0c6973affected · git
    • 459aa660eb1d8ce67080da1983bb81d716aa5a69 and later · before 3ca3da5c305caa873ddb81e8c6b118143f6dd3d1affected · git
    • 459aa660eb1d8ce67080da1983bb81d716aa5a69 and later · before 6f815c2fb6ab20385f81c353cdad0ea3b88132afaffected · git
    • 459aa660eb1d8ce67080da1983bb81d716aa5a69 and later · before e3b9aa0773abd5d4ed90be41ce5306c146d5b09eaffected · git
    • 459aa660eb1d8ce67080da1983bb81d716aa5a69 and later · before fd8396cfecbd904468c71362f08aaa25f96d5337affected · git
    • 459aa660eb1d8ce67080da1983bb81d716aa5a69 and later · before 7677eb2cbf2cc7446de474c01a6b06277c0051e5affected · git
    • 459aa660eb1d8ce67080da1983bb81d716aa5a69 and later · before 8d85498016a5bb56339734a14c276209fa65bafcaffected · git
    • 459aa660eb1d8ce67080da1983bb81d716aa5a69 and later · before d989e22ae9802c52c56ad4284d0caf26696cf6aeaffected · git
    • before 4.7not 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 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.2.6-17.2.6-1

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-2026-89787Sep 16, 2026 · ext4: check dir entry fits before reading the hash trailer in ext4_search_dir()
    0Monitor
  • ← EarlierCVE-2026-89788Sep 16, 2026 · ksmbd: fix tree connection use-after-free in smb2_tree_connect()
    39Monitor
  • Later →CVE-2026-89790Sep 16, 2026 · ipv6: avoid divide by zero in rt6_multipath_rebalance
    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 Linux3ca3da5c305caa873ddb81e8c6b118143f6dd3d1Vendor (CNA)
Linux Linux6f815c2fb6ab20385f81c353cdad0ea3b88132afVendor (CNA)
Linux Linux7677eb2cbf2cc7446de474c01a6b06277c0051e5Vendor (CNA)
Linux Linux8d85498016a5bb56339734a14c276209fa65bafcVendor (CNA)
Linux Linuxd989e22ae9802c52c56ad4284d0caf26696cf6aeVendor (CNA)
Linux Linuxe3b9aa0773abd5d4ed90be41ce5306c146d5b09eVendor (CNA)
Linux Linuxfcafb2b1430824bae4258c01a439ec97ca0c6973Vendor (CNA)
Linux Linuxfd8396cfecbd904468c71362f08aaa25f96d5337Vendor (CNA)
azl3 kernel 6.6.150.1-1 on Azure Linux 3.0—Microsoft (MSRC)
azl3 kernel 6.6.152.1-1 on Azure Linux 3.06.6.157.1-1 · Release NotesMicrosoft (MSRC)
debian:linux6.1.190-1 · Debian:12Package registry (OSV)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.111-1~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.

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.

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

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • 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
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/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. 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