Linux Kernel up to 7.2.5 gtp gtp.c gtp_newlink use after free

CVSS Meta Temp Score
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CTI Interest Score
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9.5$5k-$25k0.44

Summaryinfo

A vulnerability, which was classified as very critical, has been found in Linux Kernel up to 7.2.5. This affects the function gtp_newlink of the file gtp.c of the component gtp. Performing a manipulation results in use after free. This vulnerability is reported as CVE-2026-89789. The attack is possible to be carried out remotely. No exploit exists. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as very critical has been found in Linux Kernel up to 7.2.5. This affects the function gtp_newlink of the file gtp.c of the component gtp. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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().

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-89789 since 09/11/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/16/2026).

Upgrading to version 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, 6.18.52, 7.2.6 or 7.3-rc1 eliminates this vulnerability. Applying the patch fcafb2b1430824bae4258c01a439ec97ca0c6973/3ca3da5c305caa873ddb81e8c6b118143f6dd3d1/6f815c2fb6ab20385f81c353cdad0ea3b88132af/e3b9aa0773abd5d4ed90be41ce5306c146d5b09e/fd8396cfecbd904468c71362f08aaa25f96d5337/7677eb2cbf2cc7446de474c01a6b06277c0051e5/8d85498016a5bb56339734a14c276209fa65bafc/d989e22ae9802c52c56ad4284d0caf26696cf6ae is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-80310). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 10.0
VulDB Meta Temp Score: 9.5

VulDB Base Score: 10.0
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.270/5.15.221/6.1.188/6.6.157/6.12.110/6.18.52/7.2.6/7.3-rc1
Patch: fcafb2b1430824bae4258c01a439ec97ca0c6973/3ca3da5c305caa873ddb81e8c6b118143f6dd3d1/6f815c2fb6ab20385f81c353cdad0ea3b88132af/e3b9aa0773abd5d4ed90be41ce5306c146d5b09e/fd8396cfecbd904468c71362f08aaa25f96d5337/7677eb2cbf2cc7446de474c01a6b06277c0051e5/8d85498016a5bb56339734a14c276209fa65bafc/d989e22ae9802c52c56ad4284d0caf26696cf6ae

Timelineinfo

09/11/2026 CVE reserved
09/16/2026 +5 days Advisory disclosed
09/16/2026 +0 days VulDB entry created
09/16/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-89789 (🔒)
GCVE (CVE): GCVE-0-2026-89789
GCVE (VulDB): GCVE-100-405567
EUVD: 🔒

Entryinfo

Created: 09/16/2026 11:06
Updated: 09/16/2026 12:15
Changes: 09/16/2026 11:06 (60), 09/16/2026 12:15 (1)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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