Intel

CVE-2026-52986

Security update for the Linux Kernel

criticalEPSS 0.6%

Description

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_conntrack_sip: don't use simple_strtoul

Replace unsafe port parsing in epaddr_len(), ct_sip_parse_header_uri(), and ct_sip_parse_request() with a new sip_parse_port() helper that validates each digit against the buffer limit, eliminating the use of simple_strtoul() which assumes NUL-terminated strings.

The previous code dereferenced pointers without bounds checks after sip_parse_addr() and relied on simple_strtoul() on non-NUL-terminated skb data. A port that reaches the buffer limit without a trailing character is also rejected as malformed.

Also get rid of all simple_strtoul() usage in conntrack, prefer a stricter version instead. There are intentional changes:

  • Bail out if number is > UINT_MAX and indicate a failure, same for too long sequences. While we do accept 05535 as port 5535, we will not accept e.g. 'sip:10.0.0.1:005060'. While its syntactically valid under RFC 3261, we should restrict this to not waste cycles when presented with malformed packets with 64k '0' characters.

  • Force base 10 in ct_sip_parse_numerical_param(). This is used to fetch 'expire=' and 'rports='; both are expected to use base-10.

  • In nf_nat_sip.c, only accept the parsed value if its within the 1k-64k range.

  • epaddr_len now returns 0 if the port is invalid, as it already does for invalid ip addresses. This is intentional. nf_conntrack_sip performs lots of guesswork to find the right parts of the message to parse. Being stricter could break existing setups. Connection tracking helpers are designed to allow traffic to pass, not to block it.

Based on an earlier patch from Jenny Guanni Qu qguanni@gmail.com.

Source: SUSE_CSAFSUSE_CSAFSUSE_CSAFSUSE_CSAFSUSE_CSAFSUSE_CSAFUBUNTU_USNSIEMENS_ADVISORYUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNSUSE_CSAFUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNBSIBSI_CSAFUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNUBUNTU_USNMSRCCVELISTV5NVDCVEORG

Metrics

Severity
critical
Priority score
238.98
KEV status
—
Exploit maturity
no public PoC known
XIEM Effective CVSS
9.8
Source: cna-v3
CVSS v3
9.8
CVSS v4
—
EPSS percentile
47.6 %
High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
EPSS score
0.6 %
Low — model estimates < 1% exploitation likelihood.
Published
2026-09-09 12:14 UTC
CWE
—

Reanalysis & status changes

Chronological NVD audit events for this CVE — reanalyses, CVSS updates, CPE diffs.

  1. CVE Modified2026-09-08 09:18 UTC· 416baaa9-dc9f-4396-8d5f-8c081fb06d67
    • Reference: https://git.kernel.org/stable/c/523762e3b6933fff81f01dfa3c60c0774044cdab
    • Reference: https://git.kernel.org/stable/c/7df9863bf538a626e8a684e59cb2c43eac0ef3c8
    • Reference: https://git.kernel.org/stable/c/8cd0358379570003659186706e077929d6930c40
    • Reference: https://git.kernel.org/stable/c/8cf6809cddcbe301aedfc6b51bcd4944d45795f6
  2. CVE Modified2026-09-08 09:18 UTC· 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
    • Affected: New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/52xxx/CVE-2026-52986.json">CVE-2026-52986</a>
    • Reference: https://cert-portal.siemens.com/productcert/html/ssa-019113.html
  3. New CVE Received2026-06-24 17:17 UTC· 416baaa9-dc9f-4396-8d5f-8c081fb06d67
    • Affected: Linux, Linux
    • Description: In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_sip: don't use simple_strtoul Replace unsafe port parsing in epaddr_len(), ct_sip_parse_header_uri(), and ct_sip_parse_request() with a new sip_parse_port() helper that validates each digit against the buffer limit, eliminating the use of simple_strtoul() which assumes NUL-terminated strings. The previous code dereferenced pointers without bounds checks after sip_parse_addr() and relied on simple_strtoul() on non-NUL-terminated skb data. A port that reaches the buffer limit without a trailing character is also rejected as malformed. Also get rid of all simple_strtoul() usage in conntrack, prefer a stricter version instead. There are intentional changes: - Bail out if number is > UINT_MAX and indicate a failure, same for too long sequences. While we do accept 05535 as port 5535, we will not accept e.g. 'sip:10.0.0.1:005060'. While its syntactically valid under RFC 3261, we should restrict this to not waste cycles when presented with malformed packets with 64k '0' characters. - Force base 10 in ct_sip_parse_numerical_param(). This is used to fetch 'expire=' and 'rports='; both are expected to use base-10. - In nf_nat_sip.c, only accept the parsed value if its within the 1k-64k range. - epaddr_len now returns 0 if the port is invalid, as it already does for invalid ip addresses. This is intentional. nf_conntrack_sip performs lots of guesswork to find the right parts of the message to parse. Being stricter could break existing setups. Connection tracking helpers are designed to allow traffic to pass, not to block it. Based on an earlier patch from Jenny Guanni Qu <qguanni@gmail.com>.
    • Reference: https://git.kernel.org/stable/c/523762e3b6933fff81f01dfa3c60c0774044cdab
    • Reference: https://git.kernel.org/stable/c/7df9863bf538a626e8a684e59cb2c43eac0ef3c8

Affected operating systems

  • linux

    amazon / amazon_linux

  • linux

    suse / basesystem_module15

  • linux

    debian / debian_linux11.0

  • linux

    debian / debian_linux12.0

  • linux

    debian / debian_linux13.0

  • linux

    suse / development_tools_module15

  • linux

    redhat / enterprise_linux10.0

  • linux

    redhat / enterprise_linux8.0

  • linux

    redhat / enterprise_linux9.0

  • linux

    redhat / enterprise_linux_aus8.4

  • linux

    redhat / enterprise_linux_aus8.6

  • linux

    redhat / enterprise_linux_eus10.0

  • linux

    redhat / enterprise_linux_eus8.4

  • linux

    redhat / enterprise_linux_eus9.4

  • linux

    redhat / enterprise_linux_eus9.6

  • linux

    redhat / enterprise_linux_tus8.6

  • linux

    redhat / enterprise_linux_tus8.8

  • linux

    redhat / enterprise_linux_update_services_for_sap_solutions8.6

  • linux

    redhat / enterprise_linux_update_services_for_sap_solutions8.8

  • linux

    redhat / enterprise_linux_update_services_for_sap_solutions9.0

  • linux

    redhat / enterprise_linux_update_services_for_sap_solutions9.2

  • linux

    opensuse / leap15.3

  • linux

    opensuse / leap15.4

  • linux

    opensuse / leap15.5

Affected products

Products and version ranges extracted from the vendor/CERT advisory. A range like „<4.14.6“ implies the update recommendation „upgrade to 4.14.6 or later“.

  • AMD

    ProzessorEPYC Series

  • AMD

    ProzessorRyzen

  • arista

    cloudvision_agni2024.4.0 – 2025.2.2

  • arista

    cloudvision_portal2024.2.0 – 2026.1.0

  • arista

    velocloud_edge4.5.0 – 6.4.1

  • arista

    velocloud_gateway

  • arista

    velocloud_orchestrator

  • Dell

    NetWorkerVirtual Edition

  • Dell

    PowerProtect Data Domain7.10.1.70

  • Dell

    PowerProtect Data Domain7.13.1.40

  • Dell

    PowerProtect Data Domain8.3.1.10

  • Dell

    PowerProtect Data Domain8.4.0.0

  • IBM

    QRadar SIEM7.5.0 UP10 IF01

  • IBM

    QRadar SIEM7.5.0 UP11

  • IBM

    QRadar SIEM<7.5.0 UP15 IF06

  • IBM

    Security Guardium12

  • IBM

    Storage Scale6.1.9.5

  • IBM

    Storage Scale6.2.2.0

  • Juniper

    Junos Space24.1R2

  • Oracle

    VM3

  • redhat

    openshift_container_platform4.12 – 4.12.89

  • redhat

    openshift_container_platform4.13 – 4.13.66

  • redhat

    openshift_container_platform4.14 – 4.14.65

  • redhat

    openshift_container_platform4.15 – 4.15.64

References & sources

Linked CVEs

Show 51 more CVEs
IDCVE-2026-52986