CVE-2026-10773 (GCVE-0-2026-10773)

Vulnerability from cvelistv5 – Published: 2026-08-01 12:21 – Updated: 2026-08-03 17:50
VLAI
Title
Out-of-bounds read in DHCPv4 client message-type name lookup (net_dhcpv4_msg_type_name)
Summary
The DHCPv4 client helper net_dhcpv4_msg_type_name() in subsys/net/lib/dhcpv4/dhcpv4.c indexes a static 8-element const char * name table after a faulty bounds check. The guard used msg_type <= sizeof(name) instead of msg_type <= ARRAY_SIZE(name); sizeof returns the byte size of the pointer array (32 on 32-bit, 64 on 64-bit targets) rather than the element count of 8, so message-type values from 9 up to that byte size pass the check and cause name[msg_type - 1] to read past the end of the array. The msg_type value originates from the DHCP MESSAGE TYPE option, which is read as an unchecked raw byte from a received packet (net_pkt_read_u8) and passed unmodified into the lookup. A DHCP server, or any host able to inject a spoofed DHCP reply onto the client's link, can therefore drive the index out of bounds. The out-of-range slot yields a garbage const char * that is then dereferenced by a %s log conversion. The lookup is reached only from a debug log statement (NET_DBG / LOG_DBG), so the out-of-bounds read is triggerable only when the DHCPv4 log module is built at DEBUG level (CONFIG_NET_DHCPV4_LOG_LEVEL_DBG), which is not the default configuration. When that condition holds, the result is an out-of-bounds read and a wild-pointer dereference: most likely a crash of the DHCP client (denial of service) and potentially disclosure of an adjacent pointer's contents through the log output. The fix replaces sizeof with ARRAY_SIZE, restoring the correct 1..8 acceptance window.
SSVC
Exploitation: poc Automatable: no Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
Assigner
Impacted products
Vendor Product Version
zephyrproject zephyr Affected: 1.7.0 , < 4.5.0 (semver)
Create a notification for this product.
Show details on NVD website

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-10773",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-03T17:50:29.274490Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-03T17:50:55.197Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-r5hq-xq42-wcfq"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://github.com/zephyrproject-rtos/zephyr",
          "defaultStatus": "unaffected",
          "packageName": "zephyr",
          "product": "zephyr",
          "programFiles": [
            "subsys/net/lib/dhcpv4/dhcpv4.c",
            "subsys/net/lib/dhcpv6/dhcpv6.c"
          ],
          "vendor": "zephyrproject",
          "versions": [
            {
              "lessThan": "4.5.0",
              "status": "affected",
              "version": "1.7.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "The DHCPv4 client helper net_dhcpv4_msg_type_name() in subsys/net/lib/dhcpv4/dhcpv4.c indexes a static 8-element const char * name table after a faulty bounds check. The guard used msg_type \u003c= sizeof(name) instead of msg_type \u003c= ARRAY_SIZE(name); sizeof returns the byte size of the pointer array (32 on 32-bit, 64 on 64-bit targets) rather than the element count of 8, so message-type values from 9 up to that byte size pass the check and cause name[msg_type - 1] to read past the end of the array.\n\nThe msg_type value originates from the DHCP MESSAGE TYPE option, which is read as an unchecked raw byte from a received packet (net_pkt_read_u8) and passed unmodified into the lookup. A DHCP server, or any host able to inject a spoofed DHCP reply onto the client\u0027s link, can therefore drive the index out of bounds. The out-of-range slot yields a garbage const char * that is then dereferenced by a %s log conversion.\n\nThe lookup is reached only from a debug log statement (NET_DBG / LOG_DBG), so the out-of-bounds read is triggerable only when the DHCPv4 log module is built at DEBUG level (CONFIG_NET_DHCPV4_LOG_LEVEL_DBG), which is not the default configuration. When that condition holds, the result is an out-of-bounds read and a wild-pointer dereference: most likely a crash of the DHCP client (denial of service) and potentially disclosure of an adjacent pointer\u0027s contents through the log output. The fix replaces sizeof with ARRAY_SIZE, restoring the correct 1..8 acceptance window."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 5.4,
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L",
            "version": "3.1"
          },
          "format": "CVSS"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-125",
              "description": "bounds",
              "lang": "en",
              "type": "CWE"
            },
            {
              "cweId": "CWE-682",
              "description": "bounds",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-01T12:21:17.622Z",
        "orgId": "e2e69745-5e70-4e92-8431-deb5529a81ad",
        "shortName": "zephyr"
      },
      "references": [
        {
          "name": "Fix commit",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/zephyrproject-rtos/zephyr/commit/73c8a7df4f00088fc04ee5ab71bcabf47fcd3db7"
        },
        {
          "name": "GHSA-r5hq-xq42-wcfq",
          "url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-r5hq-xq42-wcfq"
        }
      ],
      "title": "Out-of-bounds read in DHCPv4 client message-type name lookup (net_dhcpv4_msg_type_name)",
      "x_generator": {
        "engine": "cvelib 1.8.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "e2e69745-5e70-4e92-8431-deb5529a81ad",
    "assignerShortName": "zephyr",
    "cveId": "CVE-2026-10773",
    "datePublished": "2026-08-01T12:21:17.622Z",
    "dateReserved": "2026-06-03T15:44:06.548Z",
    "dateUpdated": "2026-08-03T17:50:55.197Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-10773",
      "date": "2026-08-04",
      "epss": "0.00175",
      "percentile": "0.07259"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-10773\",\"sourceIdentifier\":\"vulnerabilities@zephyrproject.org\",\"published\":\"2026-08-01T13:16:56.987\",\"lastModified\":\"2026-08-03T19:16:41.653\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"The DHCPv4 client helper net_dhcpv4_msg_type_name() in subsys/net/lib/dhcpv4/dhcpv4.c indexes a static 8-element const char * name table after a faulty bounds check. The guard used msg_type \u003c= sizeof(name) instead of msg_type \u003c= ARRAY_SIZE(name); sizeof returns the byte size of the pointer array (32 on 32-bit, 64 on 64-bit targets) rather than the element count of 8, so message-type values from 9 up to that byte size pass the check and cause name[msg_type - 1] to read past the end of the array.\\n\\nThe msg_type value originates from the DHCP MESSAGE TYPE option, which is read as an unchecked raw byte from a received packet (net_pkt_read_u8) and passed unmodified into the lookup. A DHCP server, or any host able to inject a spoofed DHCP reply onto the client\u0027s link, can therefore drive the index out of bounds. The out-of-range slot yields a garbage const char * that is then dereferenced by a %s log conversion.\\n\\nThe lookup is reached only from a debug log statement (NET_DBG / LOG_DBG), so the out-of-bounds read is triggerable only when the DHCPv4 log module is built at DEBUG level (CONFIG_NET_DHCPV4_LOG_LEVEL_DBG), which is not the default configuration. When that condition holds, the result is an out-of-bounds read and a wild-pointer dereference: most likely a crash of the DHCP client (denial of service) and potentially disclosure of an adjacent pointer\u0027s contents through the log output. The fix replaces sizeof with ARRAY_SIZE, restoring the correct 1..8 acceptance window.\"}],\"affected\":[{\"source\":\"vulnerabilities@zephyrproject.org\",\"affectedData\":[{\"vendor\":\"zephyrproject\",\"product\":\"zephyr\",\"defaultStatus\":\"unaffected\",\"collectionURL\":\"https://github.com/zephyrproject-rtos/zephyr\",\"packageName\":\"zephyr\",\"programFiles\":[\"subsys/net/lib/dhcpv4/dhcpv4.c\",\"subsys/net/lib/dhcpv6/dhcpv6.c\"],\"versions\":[{\"version\":\"1.7.0\",\"lessThan\":\"4.5.0\",\"versionType\":\"semver\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"vulnerabilities@zephyrproject.org\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L\",\"baseScore\":5.4,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"ADJACENT_NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"LOW\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"LOW\"},\"exploitabilityScore\":2.8,\"impactScore\":2.5}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-08-03T17:50:29.274490Z\",\"id\":\"CVE-2026-10773\",\"options\":[{\"exploitation\":\"poc\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"vulnerabilities@zephyrproject.org\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-125\"},{\"lang\":\"en\",\"value\":\"CWE-682\"}]}],\"references\":[{\"url\":\"https://github.com/zephyrproject-rtos/zephyr/commit/73c8a7df4f00088fc04ee5ab71bcabf47fcd3db7\",\"source\":\"vulnerabilities@zephyrproject.org\"},{\"url\":\"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-r5hq-xq42-wcfq\",\"source\":\"vulnerabilities@zephyrproject.org\"},{\"url\":\"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-r5hq-xq42-wcfq\",\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\"}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-10773\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-08-03T17:50:29.274490Z\"}}}], \"references\": [{\"url\": \"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-r5hq-xq42-wcfq\", \"tags\": [\"exploit\"]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-08-03T17:50:49.507Z\"}}], \"cna\": {\"title\": \"Out-of-bounds read in DHCPv4 client message-type name lookup (net_dhcpv4_msg_type_name)\", \"metrics\": [{\"format\": \"CVSS\", \"cvssV3_1\": {\"version\": \"3.1\", \"baseScore\": 5.4, \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L\"}}], \"affected\": [{\"vendor\": \"zephyrproject\", \"product\": \"zephyr\", \"versions\": [{\"status\": \"affected\", \"version\": \"1.7.0\", \"lessThan\": \"4.5.0\", \"versionType\": \"semver\"}], \"packageName\": \"zephyr\", \"programFiles\": [\"subsys/net/lib/dhcpv4/dhcpv4.c\", \"subsys/net/lib/dhcpv6/dhcpv6.c\"], \"collectionURL\": \"https://github.com/zephyrproject-rtos/zephyr\", \"defaultStatus\": \"unaffected\"}], \"references\": [{\"url\": \"https://github.com/zephyrproject-rtos/zephyr/commit/73c8a7df4f00088fc04ee5ab71bcabf47fcd3db7\", \"name\": \"Fix commit\", \"tags\": [\"patch\"]}, {\"url\": \"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-r5hq-xq42-wcfq\", \"name\": \"GHSA-r5hq-xq42-wcfq\"}], \"x_generator\": {\"engine\": \"cvelib 1.8.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"The DHCPv4 client helper net_dhcpv4_msg_type_name() in subsys/net/lib/dhcpv4/dhcpv4.c indexes a static 8-element const char * name table after a faulty bounds check. The guard used msg_type \u003c= sizeof(name) instead of msg_type \u003c= ARRAY_SIZE(name); sizeof returns the byte size of the pointer array (32 on 32-bit, 64 on 64-bit targets) rather than the element count of 8, so message-type values from 9 up to that byte size pass the check and cause name[msg_type - 1] to read past the end of the array.\\n\\nThe msg_type value originates from the DHCP MESSAGE TYPE option, which is read as an unchecked raw byte from a received packet (net_pkt_read_u8) and passed unmodified into the lookup. A DHCP server, or any host able to inject a spoofed DHCP reply onto the client\u0027s link, can therefore drive the index out of bounds. The out-of-range slot yields a garbage const char * that is then dereferenced by a %s log conversion.\\n\\nThe lookup is reached only from a debug log statement (NET_DBG / LOG_DBG), so the out-of-bounds read is triggerable only when the DHCPv4 log module is built at DEBUG level (CONFIG_NET_DHCPV4_LOG_LEVEL_DBG), which is not the default configuration. When that condition holds, the result is an out-of-bounds read and a wild-pointer dereference: most likely a crash of the DHCP client (denial of service) and potentially disclosure of an adjacent pointer\u0027s contents through the log output. The fix replaces sizeof with ARRAY_SIZE, restoring the correct 1..8 acceptance window.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-125\", \"description\": \"bounds\"}, {\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-682\", \"description\": \"bounds\"}]}], \"providerMetadata\": {\"orgId\": \"e2e69745-5e70-4e92-8431-deb5529a81ad\", \"shortName\": \"zephyr\", \"dateUpdated\": \"2026-08-01T12:21:17.622Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-10773\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-08-03T17:50:55.197Z\", \"dateReserved\": \"2026-06-03T15:44:06.548Z\", \"assignerOrgId\": \"e2e69745-5e70-4e92-8431-deb5529a81ad\", \"datePublished\": \"2026-08-01T12:21:17.622Z\", \"assignerShortName\": \"zephyr\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

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.

Loading…

Detection rules are retrieved from Rulezet.

Loading…

Loading…

Loading…