OESA-2026-4100 (CVE-2026-0799)

Vulnerability from osv_openeuler – Published: 2026-09-25 01:28 – Updated: 2026-09-25 01:28 – Source website
VLAI
Summary
libpcap security update
Details

This is the official web site of tcpdump, a powerful command-line packet analyzer; and libpcap, a portable C/C++ library for network traffic capture.

Security Fix(es):

In BPF instructions that load/store a value from/to a scratch memory register the register index is an unsigned 32-bit integer and must not exceed 15, but libpcap BPF interpreter does not validate the value. In particular uncommon use cases a crafted filter program can cause the interpreter to try reading and writing the OS process memory in the 16GiB starting at the current stack frame on 64-bit architectures and in the entire address space on 32-bit architectures.(CVE-2026-0799)

The rpcap client code that processes a RPCAP_MSG_PACKET message received from the server incorrectly validates its headers. A malicious server can send a crafted message and cause the client to treat up to 20 bytes of the client process memory beyond the end of the buffer as if it was a part of the captured packet.(CVE-2026-18238)

rpcapd can allocate up to 65536 bytes per each RPCAP_MSG_UPDATEFILTER_REQ or RPCAP_MSG_STARTCAP_REQ message received from the client, but it never frees the memory, so it leaks memory even under normal use. A malicious client can cause the server to leak memory substantially faster.(CVE-2026-18313)

libpcap BPF interpreter calls abort() if it encounters a BPF instruction that has an invalid opcode. In particular uncommon use cases a crafted filter program can terminate the OS process.(CVE-2026-31911)

libpcap BPF interpreter detects neither reaching the end of the filter program buffer due to lack of a return instruction nor executing a jump instruction with an offset that translates to a pointer outside of the buffer. In particular uncommon use cases a crafted filter program can cause the interpreter to try reading the OS process memory in the 32GiB around the buffer on 64-bit architectures and in the entire address space on 32-bit architectures.(CVE-2026-31912)

libpcap BPF interpreter for the 'div #k' and 'mod #k' ALU instructions does not check whether the immediate value is zero. In particular uncommon use cases a crafted filter program can cause a division by zero.(CVE-2026-6244)

libpcap BPF interpreter treats the offset in the 'ja L' BPF instruction as a signed integer to implement looping via backward jumps, but it does not limit the number of loop iterations. In particular uncommon use cases a crafted filter program can cause the interpreter to loop infinitely.(CVE-2026-6554)

Severity
8.7 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:H
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "aarch64": [
          "libpcap-1.10.4-6.oe2403sp4.aarch64.rpm",
          "libpcap-debuginfo-1.10.4-6.oe2403sp4.aarch64.rpm",
          "libpcap-debugsource-1.10.4-6.oe2403sp4.aarch64.rpm",
          "libpcap-devel-1.10.4-6.oe2403sp4.aarch64.rpm"
        ],
        "noarch": [
          "libpcap-help-1.10.4-6.oe2403sp4.noarch.rpm"
        ],
        "src": [
          "libpcap-1.10.4-6.oe2403sp4.src.rpm"
        ],
        "x86_64": [
          "libpcap-1.10.4-6.oe2403sp4.x86_64.rpm",
          "libpcap-debuginfo-1.10.4-6.oe2403sp4.x86_64.rpm",
          "libpcap-debugsource-1.10.4-6.oe2403sp4.x86_64.rpm",
          "libpcap-devel-1.10.4-6.oe2403sp4.x86_64.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:24.03-LTS-SP4",
        "name": "libpcap",
        "purl": "pkg:rpm/openEuler/libpcap\u0026distro=openEuler-24.03-LTS-SP4"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.10.4-6.oe2403sp4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "severity": "High"
  },
  "details": "This is the official web site of tcpdump, a powerful command-line  packet analyzer; and libpcap, a portable C/C++ library for  network traffic capture.\r\n\r\nSecurity Fix(es):\n\nIn BPF instructions that load/store a value from/to a scratch memory register the register index is an unsigned 32-bit integer and must not exceed 15, but libpcap BPF interpreter does not validate the value. In particular uncommon use cases a crafted filter program can cause the interpreter to try reading and writing the OS process memory in the 16GiB starting at the current stack frame on 64-bit architectures and in the entire address space on 32-bit architectures.(CVE-2026-0799)\n\nThe rpcap client code that processes a RPCAP_MSG_PACKET message received from the server incorrectly validates its headers. A malicious server can send a crafted message and cause the client to treat up to 20 bytes of the client process memory beyond the end of the buffer as if it was a part of the captured packet.(CVE-2026-18238)\n\nrpcapd can allocate up to 65536 bytes per each RPCAP_MSG_UPDATEFILTER_REQ or RPCAP_MSG_STARTCAP_REQ message received from the client, but it never frees the memory, so it leaks memory even under normal use. A malicious client can cause the server to leak memory substantially faster.(CVE-2026-18313)\n\nlibpcap BPF interpreter calls abort() if it encounters a BPF instruction that has an invalid opcode. In particular uncommon use cases a crafted filter program can terminate the OS process.(CVE-2026-31911)\n\nlibpcap BPF interpreter detects neither reaching the end of the filter program buffer due to lack of a return instruction nor executing a jump instruction with an offset that translates to a pointer outside of the buffer. In particular uncommon use cases a crafted filter program can cause the interpreter to try reading the OS process memory in the 32GiB around the buffer on 64-bit architectures and in the entire address space on 32-bit architectures.(CVE-2026-31912)\n\nlibpcap BPF interpreter for the \u0026apos;div #k\u0026apos; and \u0026apos;mod #k\u0026apos; ALU instructions does not check whether the immediate value is zero. In particular uncommon use cases a crafted filter program can cause a division by zero.(CVE-2026-6244)\n\nlibpcap BPF interpreter treats the offset in the \u0026apos;ja L\u0026apos; BPF instruction as a signed integer to implement looping via backward jumps, but it does not limit the number of loop iterations. In particular uncommon use cases a crafted filter program can cause the interpreter to loop infinitely.(CVE-2026-6554)",
  "id": "OESA-2026-4100",
  "modified": "2026-09-25T01:28:24Z",
  "published": "2026-09-25T01:28:24Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4100"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-0799"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-18238"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-18313"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31911"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31912"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-6244"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-6554"
    }
  ],
  "schema_version": "1.7.2",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "libpcap security update",
  "upstream": [
    "CVE-2026-0799",
    "CVE-2026-18238",
    "CVE-2026-18313",
    "CVE-2026-31911",
    "CVE-2026-31912",
    "CVE-2026-6244",
    "CVE-2026-6554"
  ]
}



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