Vulnerability-Lookup

FKIE_CVE-2026-23440

Vulnerability from fkie_nvd - Published: 2026-04-03 16:16 - Updated: 2026-10-19 19:17

Severity

7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
4.7 (Medium) - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Fix race condition during IPSec ESN update In IPSec full offload mode, the device reports an ESN (Extended Sequence Number) wrap event to the driver. The driver validates this event by querying the IPSec ASO and checking that the esn_event_arm field is 0x0, which indicates an event has occurred. After handling the event, the driver must re-arm the context by setting esn_event_arm back to 0x1. A race condition exists in this handling path. After validating the event, the driver calls mlx5_accel_esp_modify_xfrm() to update the kernel's xfrm state. This function temporarily releases and re-acquires the xfrm state lock. So, need to acknowledge the event first by setting esn_event_arm to 0x1. This prevents the driver from reprocessing the same ESN update if the hardware sends events for other reason. Since the next ESN update only occurs after nearly 2^31 packets are received, there's no risk of missing an update, as it will happen long after this handling has finished. Processing the event twice causes the ESN high-order bits (esn_msb) to be incremented incorrectly. The driver then programs the hardware with this invalid ESN state, which leads to anti-replay failures and a complete halt of IPSec traffic. Fix this by re-arming the ESN event immediately after it is validated, before calling mlx5_accel_esp_modify_xfrm(). This ensures that any spurious, duplicate events are correctly ignored, closing the race window.

References

URL	Tags
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/2051c709dce92da3550040aa7949cd5a9c89b14e	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/3dffc083292e6872787bd7e34b957627622f9af4	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/8d625c15471fb8780125eaef682983a96af77bdc	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/96c9c25b74686ac2de15921c9ad30c5ef13af8cd	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/beb6e2e5976a128b0cccf10d158124422210c5ef	Patch

Impacted products

Vendor	Product	Version
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	6.4
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_offload.c"
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              "version": "6.19.10",
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              "version": "7.0",
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        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: Fix race condition during IPSec ESN update\n\nIn IPSec full offload mode, the device reports an ESN (Extended\nSequence Number) wrap event to the driver. The driver validates this\nevent by querying the IPSec ASO and checking that the esn_event_arm\nfield is 0x0, which indicates an event has occurred. After handling\nthe event, the driver must re-arm the context by setting esn_event_arm\nback to 0x1.\n\nA race condition exists in this handling path. After validating the\nevent, the driver calls mlx5_accel_esp_modify_xfrm() to update the\nkernel\u0027s xfrm state. This function temporarily releases and\nre-acquires the xfrm state lock.\n\nSo, need to acknowledge the event first by setting esn_event_arm to\n0x1. This prevents the driver from reprocessing the same ESN update if\nthe hardware sends events for other reason. Since the next ESN update\nonly occurs after nearly 2^31 packets are received, there\u0027s no risk of\nmissing an update, as it will happen long after this handling has\nfinished.\n\nProcessing the event twice causes the ESN high-order bits (esn_msb) to\nbe incremented incorrectly. The driver then programs the hardware with\nthis invalid ESN state, which leads to anti-replay failures and a\ncomplete halt of IPSec traffic.\n\nFix this by re-arming the ESN event immediately after it is validated,\nbefore calling mlx5_accel_esp_modify_xfrm(). This ensures that any\nspurious, duplicate events are correctly ignored, closing the race\nwindow."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nnet/mlx5e: Corrige condici\u00f3n de carrera durante la actualizaci\u00f3n de ESN de IPSec\n\nEn modo de descarga completa de IPSec, el dispositivo informa un evento de envoltura de ESN (N\u00famero de Secuencia Extendido) al controlador. El controlador valida este evento consultando el ASO de IPSec y verificando que el campo esn_event_arm sea 0x0, lo que indica que ha ocurrido un evento. Despu\u00e9s de manejar el evento, el controlador debe rearmar el contexto estableciendo esn_event_arm de nuevo a 0x1.\n\nExiste una condici\u00f3n de carrera en esta ruta de manejo. Despu\u00e9s de validar el evento, el controlador llama a mlx5_accel_esp_modify_xfrm() para actualizar el estado xfrm del kernel. Esta funci\u00f3n libera temporalmente y vuelve a adquirir el bloqueo de estado xfrm.\n\nPor lo tanto, es necesario reconocer el evento primero estableciendo esn_event_arm en 0x1. Esto evita que el controlador reprocese la misma actualizaci\u00f3n de ESN si el hardware env\u00eda eventos por otra raz\u00f3n. Dado que la pr\u00f3xima actualizaci\u00f3n de ESN solo ocurre despu\u00e9s de que se reciben casi 2^31 paquetes, no hay riesgo de perder una actualizaci\u00f3n, ya que ocurrir\u00e1 mucho despu\u00e9s de que este manejo haya terminado.\n\nProcesar el evento dos veces hace que los bits de orden superior de ESN (esn_msb) se incrementen incorrectamente. El controlador luego programa el hardware con este estado ESN inv\u00e1lido, lo que lleva a fallos de anti-replay y una detenci\u00f3n completa del tr\u00e1fico IPSec.\n\nSolucione esto rearmando el evento ESN inmediatamente despu\u00e9s de que sea validado, antes de llamar a mlx5_accel_esp_modify_xfrm(). Esto asegura que cualquier evento espurio o duplicado sea correctamente ignorado, cerrando la ventana de carrera."
    }
  ],
  "id": "CVE-2026-23440",
  "lastModified": "2026-10-19T19:17:48.243",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      },
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          "availabilityImpact": "HIGH",
          "baseScore": 4.7,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
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        "impactScore": 3.6,
        "source": "nvd@nist.gov",
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    "ssvcV203": [
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          "options": [
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            },
            {
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            },
            {
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          "role": "CISA Coordinator",
          "timestamp": "2026-10-16T15:08:06.738752Z",
          "version": "2.0.3"
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  "published": "2026-04-03T16:16:26.020",
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  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Modified",
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          "lang": "en",
          "value": "CWE-362"
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      "type": "Primary"
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          "value": "CWE-362"
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}

CVE-2026-23440 (GCVE-0-2026-23440)

Vulnerability from cvelistv5 – Published: 2026-04-03 15:15 – Updated: 2026-10-19 18:35

Title

net/mlx5e: Fix race condition during IPSec ESN update

Summary

Severity

7.5 (High)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-16 15:08 UTC

CWE

CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 6639 records in the last 180 days details

References

5 references

URL	Tags
https://git.kernel.org/stable/c/3dffc083292e68727…
https://git.kernel.org/stable/c/2051c709dce92da35…
https://git.kernel.org/stable/c/96c9c25b74686ac2d…
https://git.kernel.org/stable/c/8d625c15471fb8780…
https://git.kernel.org/stable/c/beb6e2e5976a128b0…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: fef06678931ff67b158d337b581e5cf5ca40a3a3 , < 3dffc083292e6872787bd7e34b957627622f9af4 (git) Affected: fef06678931ff67b158d337b581e5cf5ca40a3a3 , < 2051c709dce92da3550040aa7949cd5a9c89b14e (git) Affected: fef06678931ff67b158d337b581e5cf5ca40a3a3 , < 96c9c25b74686ac2de15921c9ad30c5ef13af8cd (git) Affected: fef06678931ff67b158d337b581e5cf5ca40a3a3 , < 8d625c15471fb8780125eaef682983a96af77bdc (git) Affected: fef06678931ff67b158d337b581e5cf5ca40a3a3 , < beb6e2e5976a128b0cccf10d158124422210c5ef (git)
Linux	Linux	Affected: 6.4 Unaffected: 0 , < 6.4 (semver) Unaffected: 6.6.130 , ≤ 6.6.* (semver) Unaffected: 6.12.78 , ≤ 6.12.* (semver) Unaffected: 6.18.20 , ≤ 6.18.* (semver) Unaffected: 6.19.10 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-23440",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-16T15:08:06.738752Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-362",
                "description": "CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization (\u0027Race Condition\u0027)",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-19T18:35:43.781Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
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          "product": "Linux",
          "programFiles": [
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              "versionType": "git"
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            {
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              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.78",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.20",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.130",
                  "versionStartIncluding": "6.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.78",
                  "versionStartIncluding": "6.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.20",
                  "versionStartIncluding": "6.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.10",
                  "versionStartIncluding": "6.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "versionStartIncluding": "6.4",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: Fix race condition during IPSec ESN update\n\nIn IPSec full offload mode, the device reports an ESN (Extended\nSequence Number) wrap event to the driver. The driver validates this\nevent by querying the IPSec ASO and checking that the esn_event_arm\nfield is 0x0, which indicates an event has occurred. After handling\nthe event, the driver must re-arm the context by setting esn_event_arm\nback to 0x1.\n\nA race condition exists in this handling path. After validating the\nevent, the driver calls mlx5_accel_esp_modify_xfrm() to update the\nkernel\u0027s xfrm state. This function temporarily releases and\nre-acquires the xfrm state lock.\n\nSo, need to acknowledge the event first by setting esn_event_arm to\n0x1. This prevents the driver from reprocessing the same ESN update if\nthe hardware sends events for other reason. Since the next ESN update\nonly occurs after nearly 2^31 packets are received, there\u0027s no risk of\nmissing an update, as it will happen long after this handling has\nfinished.\n\nProcessing the event twice causes the ESN high-order bits (esn_msb) to\nbe incremented incorrectly. The driver then programs the hardware with\nthis invalid ESN state, which leads to anti-replay failures and a\ncomplete halt of IPSec traffic.\n\nFix this by re-arming the ESN event immediately after it is validated,\nbefore calling mlx5_accel_esp_modify_xfrm(). This ensures that any\nspurious, duplicate events are correctly ignored, closing the race\nwindow."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - The vulnerable ESN update path is driven by mlx5 IPsec full-offload hardware events caused by ESP traffic on an offloaded SA, so a remote IPsec peer can reach it over the network in a reasonable VPN/gateway deployment.\nAC:L - The triggering conditions are traffic volume and event timing on an active ESN SA; the attacker can drive repeated packet processing and, under the required overestimate rule, the race is treated as practically triggerable.\nPR:N - No local kernel privilege is needed to send traffic to an already configured IPsec endpoint; although valid SA traffic may be required, the runtime trigger is network packet processing rather than a privileged local ioctl/netlink operation.\nUI:N - Once the affected mlx5 IPsec offload SA exists, exploitation does not require a victim user to perform any action.\nS:U - The impact remains within the same kernel/networking security authority and does not cross a VM, IOMMU, or sandbox boundary.\nC:N - The bug corrupts ESN accounting/state and causes packet rejection, but there is no evidence of information disclosure or arbitrary memory read.\nI:N - The invalid esn_msb state does not give an attacker data modification, arbitrary write, or code execution; it results in anti-replay failures.\nA:H - Processing the ESN event twice programs invalid hardware ESN state, leading to anti-replay failures and a complete halt of affected IPsec traffic."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:21:46.631Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/3dffc083292e6872787bd7e34b957627622f9af4"
        },
        {
          "url": "https://git.kernel.org/stable/c/2051c709dce92da3550040aa7949cd5a9c89b14e"
        },
        {
          "url": "https://git.kernel.org/stable/c/96c9c25b74686ac2de15921c9ad30c5ef13af8cd"
        },
        {
          "url": "https://git.kernel.org/stable/c/8d625c15471fb8780125eaef682983a96af77bdc"
        },
        {
          "url": "https://git.kernel.org/stable/c/beb6e2e5976a128b0cccf10d158124422210c5ef"
        }
      ],
      "title": "net/mlx5e: Fix race condition during IPSec ESN update",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-23440",
    "datePublished": "2026-04-03T15:15:24.596Z",
    "dateReserved": "2026-01-13T15:37:46.017Z",
    "dateUpdated": "2026-10-19T18:35:43.781Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Publication & reservation Sightings KEV catalogs Other timestamps

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

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