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TencentOS Server 4: pcs (TSSA-2026:0801)

🗓️ 12 Aug 2026 00:00:00Reported by TenableType 
nessus
 nessus
🔗 www.tenable.com👁 8 Views

TencentOS Server 4 affected by Puma IP spoofing and DoS via PROXY protocol CVE-2026-47736 and CVE-2026-47737.

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Refs
Code
ReporterTitlePublishedViews
Family
attackerkb
ATTACKERKB
CVE-2026-47736
14 Jul 202619:54
attackerkb
attackerkb
ATTACKERKB
CVE-2026-47737
14 Jul 202619:45
attackerkb
cgr
Chainguard
CVE-2026-47736 vulnerabilities
10 Jun 202607:25
cgr
cgr
Chainguard
CVE-2026-47737 vulnerabilities
10 Jun 202607:25
cgr
cve
CVE
CVE-2026-47736
14 Jul 202619:54
cve
cve
CVE
CVE-2026-47737
14 Jul 202619:45
cve
cvelist
Cvelist
CVE-2026-47736 Puma PROXY Protocol v1 Parser Allows Remote Memory Exhaustion
14 Jul 202619:54
cvelist
cvelist
Cvelist
CVE-2026-47737 Puma PROXY Protocol v1 Accepts Repeated Protocol Headers on Persistent Connections
14 Jul 202619:45
cvelist
debiancve
Debian CVE
CVE-2026-47736
14 Jul 202619:54
debiancve
debiancve
Debian CVE
CVE-2026-47737
14 Jul 202619:45
debiancve
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#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Tencent Linux Security Advisory TSSA-2026:0801.
##

include('compat.inc');

if (description)
{
  script_id(334830);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/12");

  script_cve_id("CVE-2026-47736", "CVE-2026-47737");

  script_name(english:"TencentOS Server 4: pcs (TSSA-2026:0801)");

  script_set_attribute(attribute:"synopsis", value:
"The remote TencentOS Server 4 host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The version of Tencent Linux installed on the remote TencentOS Server 4 host is prior to tested version. It is,
therefore, affected by multiple vulnerabilities as referenced in the TSSA-2026:0801 advisory.

    Package updates are available for TencentOS Server 4 that fix the following vulnerabilities:

    CVE-2026-47737:
    Puma is a Ruby/Rack web server built for parallelism. From 5.5.0 until 7.2.1 and 8.0.2, Puma is vulnerable
    to source IP spoofing when set_remote_address proxy_protocol: :v1 is enabled and persistent connections
    are used because Puma incorrectly re-parses PROXY protocol headers after each keep-alive request on the
    same connection, allowing an attacker to inject a second PROXY header and overwrite REMOTE_ADDR. This
    issue is fixed in versions 7.2.1 and 8.0.2.

    CVE-2026-47736:
    Puma is a Ruby/Rack web server built for parallelism. From 5.5.0 until 7.2.1 and 8.0.2, when PROXY
    protocol v1 support is enabled, Puma reads incoming bytes into an internal buffer while waiting for CRLF
    to determine whether a PROXY v1 line is present, allowing an attacker that continuously sends bytes
    without CRLF to cause unbounded in-process memory growth and additional CPU cost from repeatedly scanning
    the growing buffer. This issue is fixed in versions 7.2.1 and 8.0.2.

Tenable has extracted the preceding description block directly from the Tencent Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://mirrors.tencent.com/tlinux/errata/tssa-20260801.xml");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:C/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-47737");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/06/08");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/11");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/12");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:tencent:tencentos_server:4");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:tencent:tencentos_server:pcs");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Tencent Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info2.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/etc/os-release", "Host/TencentOS/rpm-list", "Host/cpu");

  exit(0);
}


include('rpm2.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_product = get_kb_item('installed_os/local/SSH/0/product');
if (isnull(os_product) || 'TencentOS' >!< os_product) audit(AUDIT_OS_NOT, 'TencentOS');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'TencentOS');
if (! preg(pattern:"^4([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'TencentOS 4.x', 'TencentOS ' + os_version);

if (!get_kb_item('Host/TencentOS/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'TencentOS', cpu);

var constraints = [
  {
    'release': '4',
    'pkgs': [
      {'reference':'pcs-0.11.5-23.tl4.ap.1', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'pcs-0.11.5-23.tl4.ap.1', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'pcs-snmp-0.11.5-23.tl4.ap.1', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'pcs-snmp-0.11.5-23.tl4.ap.1', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE}
    ]
  }
];

var os_release = get_one_kb_item('installed_os/local/SSH/0/release');
var os_sp = get_one_kb_item('Host/*/minor_release');

var flag = 0;
var reference;
var sp;
var _cpu;
var el_string;
var rpm_spec_vers_cmp;
var epoch;
var allowmaj;
var exists_check;
var cves;
foreach var constraint ( constraints ) {
  # Check that the target release is equal to the affected release
  if (!empty_or_null(constraint['release'])){
    if (constraint['release'] != os_release) continue;
  }
  if (!empty_or_null(constraint['sp'])){
    if (constraint['sp'] != os_sp) continue;
  }
  foreach var pkg ( constraint['pkgs'] ) {
    reference = NULL;
    sp = NULL;
    _cpu = NULL;
    el_string = NULL;
    rpm_spec_vers_cmp = NULL;
    epoch = NULL;
    allowmaj = NULL;
    exists_check = NULL;
    cves = NULL;
    if (!empty_or_null(pkg['reference'])) reference = pkg['reference'];
    if (!empty_or_null(pkg['sp'])) sp = pkg['sp'];
    if (!empty_or_null(pkg['cpu'])) _cpu = pkg['cpu'];
    if (!empty_or_null(pkg['el_string'])) el_string = pkg['el_string'];
    if (!empty_or_null(pkg['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = pkg['rpm_spec_vers_cmp'];
    if (!empty_or_null(pkg['epoch'])) epoch = pkg['epoch'];
    if (!empty_or_null(pkg['allowmaj'])) allowmaj = pkg['allowmaj'];
    if (!empty_or_null(pkg['exists_check'])) exists_check = pkg['exists_check'];
    if (!empty_or_null(pkg['cves'])) cves = pkg['cves'];
    if (reference &&
        ## (no known rpm to check OR known rpm_exists)
        (!exists_check || rpm_exists(rpm:exists_check)) &&
        rpm_check(sp:sp, cpu:_cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj, cves:cves)) flag++;
  }
}

if (flag)
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_HOLE,
      extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'pcs / pcs-snmp');
}

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12 Aug 2026 00:00Current
5.9Medium risk
Vulners AI Score5.9
CVSS 3.17.5
EPSS0.0063
SSVC
8