Linux Kernel up to 7.3-rc4 flowtable flow_offload_work_del use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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9.5$5k-$25k1.80-

Summaryinfo

A vulnerability identified as very critical has been detected in Linux Kernel up to 7.3-rc4. The impacted element is the function flow_offload_work_del of the component flowtable. The manipulation leads to use after free. This vulnerability is referenced as CVE-2026-98625. Remote exploitation of the attack is possible. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as very critical, has been found in Linux Kernel up to 7.3-rc4. This issue affects the function flow_offload_work_del of the component flowtable. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: netfilter: flowtable: publish HW_DEAD after worker is done flow_offload_work_del() sets NF_FLOW_HW_DEAD before the work handler clears NF_FLOW_HW_PENDING. Once a flow is both HW_DYING and HW_DEAD, a concurrent garbage collection pass can remove it and schedule it for RCU freeing. The offload worker holds neither an RCU read lock nor a reference to the flow. If it is preempted after publishing HW_DEAD, the RCU callback can free the flow before the worker resumes and clears HW_PENDING, resulting in a use-after-free. Move HW_DEAD publication to the common worker epilogue after the pending bit is cleared, making it the final flow access by destroy work. Order all preceding flow accesses before publishing the bit that allows garbage collection to free the object.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2026-98625 since 09/25/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details are known, but no exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 10/18/2026).

Upgrading to version 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.55, 7.2.9 or 7.3-rc5 eliminates this vulnerability. Applying the patch f92e8f39726ba68a7c42c6b7566be687c8161579/00e452a7ca9fda135ea3d04a11128d5088e354a8/56f39c7d139bb76072efe2fb3dcafc13ba915ad8/e20701843032c438f879066a77ea85e361c6b999/b4f0f05dfbe836a171bff261f17d098a4d5461ea/b0ef9450e93f2adeb77593db14c2ac7c6c8f5060/f26652e99f519e6bd34f8a9b48fbb33c603585f2/d644b23afe1ef509c9961a6d84a093c2587edf02 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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Version

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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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💳💳💳💳💳💳
💳💳💳💳💳💳
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 5.10.271/5.15.222/6.1.189/6.6.158/6.12.112/6.18.55/7.2.9/7.3-rc5
Patch: f92e8f39726ba68a7c42c6b7566be687c8161579/00e452a7ca9fda135ea3d04a11128d5088e354a8/56f39c7d139bb76072efe2fb3dcafc13ba915ad8/e20701843032c438f879066a77ea85e361c6b999/b4f0f05dfbe836a171bff261f17d098a4d5461ea/b0ef9450e93f2adeb77593db14c2ac7c6c8f5060/f26652e99f519e6bd34f8a9b48fbb33c603585f2/d644b23afe1ef509c9961a6d84a093c2587edf02

Timelineinfo

09/25/2026 CVE reserved
10/18/2026 +23 days Advisory disclosed
10/18/2026 +0 days VulDB entry created
10/18/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-98625 (🔒)
GCVE (CVE): GCVE-0-2026-98625
GCVE (VulDB): GCVE-100-422165

Entryinfo

Created: 10/18/2026 20:47
Changes: 10/18/2026 20:47 (59)
Complete: 🔍
Cache ID: 216::103

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