CVE-2026-16821 (GCVE-0-2026-16821)

Vulnerability from cvelistv5 – Published: 2026-08-28 20:43 – Updated: 2026-08-31 13:51
VLAI
Title
Vulnerabilities in IBM AIX and PowerVM VIOS
Summary
IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a local attacker to gain elevated privileges due to a format string vulnerability.
Severity
7 (High)
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-31 13:51 UTC
CWE
  • CWE-134 - Use of Externally-Controlled Format String
Assigner
References
URL Tags
https://www.ibm.com/support/pages/node/7283858 vendor-advisorypatch
Impacted products
Vendor Product Version CPE status
IBM AIX Affected: 7.2
Affected: 7.3
    cpe:2.3:a:ibm:aix:7.2:*:*:*:*:*:*:*
    cpe:2.3:a:ibm:aix:7.2.0:*:*:*:*:*:*:*
    cpe:2.3:a:ibm:aix:7.3:*:*:*:*:*:*:*
    cpe:2.3:a:ibm:aix:7.3.0:*:*:*:*:*:*:*
Create a notification for this product.
IBM PowerVM VIOS Affected: 4.1
    cpe:2.3:a:ibm:powervm_vios:4.1:*:*:*:*:*:*:*
    cpe:2.3:a:ibm:powervm_vios:4.1.0:*:*:*:*:*:*:*
Create a notification for this product.
Credits
CVE-2026-14970, CVE-2026-15061, CVE-2026-15078, CVE-2026-15065, CVE-2026-15068 were reported to IBM by Oneconsult AG (https://oneconsult.com/).
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-16821",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-31T13:51:46.699795Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-31T13:51:59.666Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "cpes": [
            "cpe:2.3:a:ibm:aix:7.2:*:*:*:*:*:*:*",
            "cpe:2.3:a:ibm:aix:7.2.0:*:*:*:*:*:*:*",
            "cpe:2.3:a:ibm:aix:7.3:*:*:*:*:*:*:*",
            "cpe:2.3:a:ibm:aix:7.3.0:*:*:*:*:*:*:*"
          ],
          "product": "AIX",
          "vendor": "IBM",
          "versions": [
            {
              "status": "affected",
              "version": "7.2"
            },
            {
              "status": "affected",
              "version": "7.3"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:ibm:powervm_vios:4.1:*:*:*:*:*:*:*",
            "cpe:2.3:a:ibm:powervm_vios:4.1.0:*:*:*:*:*:*:*"
          ],
          "product": "PowerVM VIOS",
          "vendor": "IBM",
          "versions": [
            {
              "status": "affected",
              "version": "4.1"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "CVE-2026-14970, CVE-2026-15061, CVE-2026-15078, CVE-2026-15065, CVE-2026-15068 were reported to IBM by Oneconsult AG (https://oneconsult.com/)."
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003eIBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a local attacker to gain elevated privileges due to a format string vulnerability.\u003c/p\u003e"
            }
          ],
          "value": "IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a local attacker to gain elevated privileges due to a format string vulnerability."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 7,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-134",
              "description": "CWE-134 Use of Externally-Controlled Format String",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-28T20:43:04.351Z",
        "orgId": "9a959283-ebb5-44b6-b705-dcc2bbced522",
        "shortName": "ibm"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory",
            "patch"
          ],
          "url": "https://www.ibm.com/support/pages/node/7283858"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003e\u003cstrong\u003eA.\u00a0 APARS\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eIBM has assigned the following APARs to this problem:\u003c/p\u003e\u003cdiv\u003e\u003ctable\u003e\u003ccolgroup\u003e\u003ccol/\u003e\u003ccol/\u003e\u003ccol/\u003e\u003ccol/\u003e\u003ccol/\u003e\u003c/colgroup\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd\u003e\u003cstrong\u003eAIX Level\u003c/strong\u003e\u003c/td\u003e\u003ctd\u003e\u003cstrong\u003eAPAR\u003c/strong\u003e\u003c/td\u003e\u003ctd\u003e\u003cstrong\u003eAvailability\u00a0\u00a0\u003c/strong\u003e\u003c/td\u003e\u003ctd\u003e\u003cstrong\u003eSP\u003c/strong\u003e\u003c/td\u003e\u003ctd\u003e\u003cstrong\u003eKEY\u003c/strong\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd\u003e7.2.5\u003c/td\u003e\u003ctd\u003eIJ59566\u003c/td\u003e\u003ctd\u003e08/14/2026\u003c/td\u003e\u003ctd\u003eSP13\u003c/td\u003e\u003ctd\u003ekey_w_apar\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd\u003e7.3.2\u003c/td\u003e\u003ctd\u003eIJ59565\u003c/td\u003e\u003ctd\u003e08/14/2026\u003c/td\u003e\u003ctd\u003eSP05\u003c/td\u003e\u003ctd\u003ekey_w_apar\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd\u003e7.3.3\u003c/td\u003e\u003ctd\u003eIJ59564\u003c/td\u003e\u003ctd\u003e08/14/2026\u003c/td\u003e\u003ctd\u003eSP03\u003c/td\u003e\u003ctd\u003ekey_w_apar\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd\u003e7.3.4\u003c/td\u003e\u003ctd\u003eIJ59563\u00a0\u003c/td\u003e\u003ctd\u003e08/14/2026\u003c/td\u003e\u003ctd\u003eSP02\u003c/td\u003e\u003ctd\u003ekey_w_apar\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e\u003cp\u003e\u003c/p\u003e\u003cdiv\u003e\u003ctable\u003e\u003ccolgroup\u003e\u003ccol/\u003e\u003ccol/\u003e\u003ccol/\u003e\u003ccol/\u003e\u003ccol/\u003e\u003c/colgroup\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd\u003e\u003cstrong\u003eVIOS Level\u003c/strong\u003e\u003c/td\u003e\u003ctd\u003e\u003cstrong\u003eAPAR\u003c/strong\u003e\u003c/td\u003e\u003ctd\u003e\u003cstrong\u003eAvailability\u00a0\u003c/strong\u003e\u003c/td\u003e\u003ctd\u003e\u003cstrong\u003eSP\u003c/strong\u003e\u003c/td\u003e\u003ctd\u003e\u003cstrong\u003eKEY\u003c/strong\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd\u003e4.1.0\u003c/td\u003e\u003ctd\u003eIJ59565\u003c/td\u003e\u003ctd\u003e08/14/2026\u003c/td\u003e\u003ctd\u003e4.1.0.50\u003c/td\u003e\u003ctd\u003ekey_w_apar\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd\u003e4.1.1\u003c/td\u003e\u003ctd\u003eIJ59564\u003c/td\u003e\u003ctd\u003e08/14/2026\u003c/td\u003e\u003ctd\u003e4.1.1.30\u003c/td\u003e\u003ctd\u003ekey_w_apar\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd\u003e4.1.2\u003c/td\u003e\u003ctd\u003eIJ59563\u003c/td\u003e\u003ctd\u003e08/14/2026\u003c/td\u003e\u003ctd\u003e4.1.2.20\u003c/td\u003e\u003ctd\u003ekey_w_apar\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eB.\u00a0 FIXES\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eIBM strongly recommends addressing the vulnerability now.\u003c/p\u003e\u003cp\u003e\u00a0AIX and VIOS fixes are available and can be downloaded from Fix Central: \u003ca href=\"https://www.ibm.com/support/fixcentral\" rel=\"nofollow\"\u003ehttps://www.ibm.com/support/fixcentral\u003c/a\u003e\u003c/p\u003e\u003cp\u003e\u00a0An LPAR reboot is required to complete the SP/FP update. On AIX, Live Update can be used to avoid a reboot.\u003c/p\u003e\u003cp\u003e\u00a0IBM has assigned the following AIX Service Packs (SPs) and VIOS Fix Packs (FPs) as the remediation levels for the published vulnerabilities.\u003c/p\u003e\u003cdiv\u003e\u003ctable\u003e\u003ccolgroup\u003e\u003ccol/\u003e\u003ccol/\u003e\u003c/colgroup\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd\u003e\u003cstrong\u003eAIX Level\u00a0\u003c/strong\u003e\u003c/td\u003e\u003ctd\u003e\u003cstrong\u003eService Pack\u003c/strong\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd\u003eAIX 7.3 TL04\u003c/td\u003e\u003ctd\u003eSP2\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd\u003eAIX 7.3 TL03\u003c/td\u003e\u003ctd\u003eSP3\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd\u003eAIX 7.3 TL02\u003c/td\u003e\u003ctd\u003eSP5\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd\u003eAIX 7.2 TL05\u00a0\u003c/td\u003e\u003ctd\u003eSP13\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e\u003cp\u003e\u003c/p\u003e\u003cdiv\u003e\u003ctable\u003e\u003ccolgroup\u003e\u003ccol/\u003e\u003ccol/\u003e\u003c/colgroup\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd\u003e\u003cstrong\u003ePowerVM VIOS Level\u003c/strong\u003e\u003c/td\u003e\u003ctd\u003e\u003cstrong\u003eFix Pack\u003c/strong\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd\u003eVIOS 4.1.2\u00a0\u003c/td\u003e\u003ctd\u003e4.1.2.20\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd\u003eVIOS 4.1.1\u00a0\u003c/td\u003e\u003ctd\u003e4.1.1.30\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd\u003eVIOS 4.1.0\u00a0\u00a0\u003c/td\u003e\u003ctd\u003e4.1.0.50\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eNote:\u003c/strong\u003e These SPs/FPs are cumulative and include fixes for all previously published AIX/VIOS security vulnerabilities. They can be applied on top of any earlier affected level of the TL .\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eNote:\u003c/strong\u003e To apply these patches using nimsh secure, special steps must be taken as the protocol between master and client is updated to be more secure. Please read this article:\u003cbr/\u003e\u003ca href=\"https://www.ibm.com/support/pages/node/7283157\" rel=\"nofollow\"\u003ehttps://www.ibm.com/support/pages/node/7283157\u003c/a\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eNote:\u003c/strong\u003e For VIOS 4.1.0 and VIOS 4.1.1, additional steps are required to migrate to the latest Postgres15 after applying the 4.1.1.30 or 4.1.0.50 FPs above. Instructions to do that can be found here:\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0\u003c/p\u003e\u003cp\u003e\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 4.1.0.50 post-update instructions: \u003ca href=\"https://www.ibm.com/support/pages/node/7283819\" rel=\"nofollow\"\u003ehttps://www.ibm.com/support/pages/node/7283819\u003c/a\u003e\u003cbr/\u003e\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 4.1.1.30 post-update instructions: \u003ca href=\"https://www.ibm.com/support/pages/node/7283823\" rel=\"nofollow\"\u003ehttps://www.ibm.com/support/pages/node/7283823\u003c/a\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"
            }
          ],
          "value": "A.\u00a0 APARS\n\n\n\nIBM has assigned the following APARs to this problem:\n\nAIX LevelAPARAvailability\u00a0\u00a0SPKEY7.2.5IJ5956608/14/2026SP13key_w_apar7.3.2IJ5956508/14/2026SP05key_w_apar7.3.3IJ5956408/14/2026SP03key_w_apar7.3.4IJ59563\u00a008/14/2026SP02key_w_apar\n\n\n\n\n\nVIOS LevelAPARAvailability\u00a0SPKEY4.1.0IJ5956508/14/20264.1.0.50key_w_apar4.1.1IJ5956408/14/20264.1.1.30key_w_apar4.1.2IJ5956308/14/20264.1.2.20key_w_apar\n\n\n\n\n\n\n\nB.\u00a0 FIXES\n\n\n\nIBM strongly recommends addressing the vulnerability now.\n\n\n\n\u00a0AIX and VIOS fixes are available and can be downloaded from Fix Central:  https://www.ibm.com/support/fixcentral \n\n\n\n\u00a0An LPAR reboot is required to complete the SP/FP update. On AIX, Live Update can be used to avoid a reboot.\n\n\n\n\u00a0IBM has assigned the following AIX Service Packs (SPs) and VIOS Fix Packs (FPs) as the remediation levels for the published vulnerabilities.\n\nAIX Level\u00a0Service PackAIX 7.3 TL04SP2AIX 7.3 TL03SP3AIX 7.3 TL02SP5AIX 7.2 TL05\u00a0SP13\n\n\n\n\n\nPowerVM VIOS LevelFix PackVIOS 4.1.2\u00a04.1.2.20VIOS 4.1.1\u00a04.1.1.30VIOS 4.1.0\u00a0\u00a04.1.0.50\n\n\n\n\n\n\n\nNote: These SPs/FPs are cumulative and include fixes for all previously published AIX/VIOS security vulnerabilities. They can be applied on top of any earlier affected level of the TL .\n\n\n\nNote: To apply these patches using nimsh secure, special steps must be taken as the protocol between master and client is updated to be more secure. Please read this article:\n https://www.ibm.com/support/pages/node/7283157 \n\n\n\nNote: For VIOS 4.1.0 and VIOS 4.1.1, additional steps are required to migrate to the latest Postgres15 after applying the 4.1.1.30 or 4.1.0.50 FPs above. Instructions to do that can be found here:\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0\n\n\n\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 4.1.0.50 post-update instructions:  https://www.ibm.com/support/pages/node/7283819 \n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 4.1.1.30 post-update instructions:  https://www.ibm.com/support/pages/node/7283823"
        }
      ],
      "title": "Vulnerabilities in IBM AIX and PowerVM VIOS"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9a959283-ebb5-44b6-b705-dcc2bbced522",
    "assignerShortName": "ibm",
    "cveId": "CVE-2026-16821",
    "datePublished": "2026-08-28T20:43:04.351Z",
    "dateReserved": "2026-07-24T02:06:36.026Z",
    "dateUpdated": "2026-08-31T13:51:59.666Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-16821",
      "date": "2026-08-31",
      "epss": "0.00096",
      "percentile": "0.00784"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-16821\",\"sourceIdentifier\":\"psirt@us.ibm.com\",\"published\":\"2026-08-28T22:16:46.310\",\"lastModified\":\"2026-08-28T22:16:46.310\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a local attacker to gain elevated privileges due to a format string vulnerability.\"}],\"affected\":[{\"source\":\"psirt@us.ibm.com\",\"affectedData\":[{\"vendor\":\"IBM\",\"product\":\"AIX\",\"cpes\":[\"cpe:2.3:a:ibm:aix:7.2:*:*:*:*:*:*:*\",\"cpe:2.3:a:ibm:aix:7.2.0:*:*:*:*:*:*:*\",\"cpe:2.3:a:ibm:aix:7.3:*:*:*:*:*:*:*\",\"cpe:2.3:a:ibm:aix:7.3.0:*:*:*:*:*:*:*\"],\"versions\":[{\"version\":\"7.2\",\"status\":\"affected\"},{\"version\":\"7.3\",\"status\":\"affected\"}]},{\"vendor\":\"IBM\",\"product\":\"PowerVM VIOS\",\"cpes\":[\"cpe:2.3:a:ibm:powervm_vios:4.1:*:*:*:*:*:*:*\",\"cpe:2.3:a:ibm:powervm_vios:4.1.0:*:*:*:*:*:*:*\"],\"versions\":[{\"version\":\"4.1\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"psirt@us.ibm.com\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":7.0,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"HIGH\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.0,\"impactScore\":5.9}]},\"weaknesses\":[{\"source\":\"psirt@us.ibm.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-134\"}]}],\"references\":[{\"url\":\"https://www.ibm.com/support/pages/node/7283858\",\"source\":\"psirt@us.ibm.com\"}]}}"
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.


Detection rules are retrieved from Rulezet.