CVE-2026-23457

HIGHPre-NVD 8.68.6—
EchelonGraph scoreMEDIUM confidence

Score 8.6 from GitHub Security Advisory (severity: HIGH) published 2026-04-03. the CNA's CVSS baseline 8.6; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:linux, epss, ghsa
8.6EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.6Exploit: None knownExposed: 0

A fix is available — apply it.

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

netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp()

sip_help_tcp() parses the SIP Content-Length header with simple_strtoul(), which returns unsigned long, but stores the result in unsigned int clen. On 64-bit systems, values exceeding UINT_MAX are silently truncated before computing the SIP message boundary.

For example, Content-Length 4294967328 (2^32 + 32) is truncated to 32, causing the parser to miscalculate where the current message ends. The loop then treats trailing data in the TCP segment as a second SIP message and processes it through the SDP parser.

Fix this by changing clen to unsigned long to match the return type of simple_strtoul(), and reject Content-Length values that exceed the remaining TCP payload length.

CVSS v3
8.6
EG Score
8.6(medium)
EG Risk
43(Track)
EG Risk 43/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity86% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
37%
KEV
Not listed

Published

April 3, 2026

Last Modified

September 8, 2026

Advisory Details (8)

Auto-updated May 3, 2026
No patch confirmed yet.
generic

netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/fbce58e719a17aa215c724473fd5baaa4a8dc57c
generic

netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ed81b6a7012485acdb9c6c80735a0b7d8e5e1873
generic

netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/d4f17256544cc37f6534a14a27a9dec3540c2015
generic

netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/cd1b7403ec835f8a0b3f1f7e68ac26af2cb1e42f
generic

netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/b75209debb9adab287b3caa982f77788c1e15027
generic

netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/865dba58958c3a86786f89a501971ab0e3ec6ba9
generic

netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/75fcaee5170e7dbbee778927134ef2e9568b4659
generic

netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/528b4509c9dfc272e2e92d811915e5211650d383

Vendor Advisories for CVE-2026-23457(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(27)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-virtual-6.8 (6.8.0-136.136) @ noble2026-09-08ubuntu
ubuntulinux-tools-raspi-realtime-6.8 (6.8.0-2050.52) @ noble2026-09-08ubuntu
ubuntulinux-tools-gcp-fips-6.8 (6.8.0-1064.72+fips1) @ noble2026-09-08ubuntu
ubuntulinux-xilinx-zynqmp-tools-5.15.0-1075 (5.15.0-1075.79) @ jammy2026-09-08ubuntu
ubuntulinux-tools-nvidia-tegra-rt-5.15 (5.15.0.1064.66~20.04.1) @ focal2026-09-08ubuntu
ubuntulinux-tools-oracle-lts-24.04 (6.8.0-1058.61) @ noble2026-09-08ubuntu
ubuntulinux-tools-oracle-edge (6.8.0-1058.61~22.04.1) @ jammy2026-09-08ubuntu
ubuntulinux-tools-nvidia-lowlatency-64k-6.8 (6.8.0-1059.62.1) @ noble2026-09-08ubuntu
ubuntulinux-tools-nvidia-lowlatency-5.15 (5.15.0.1107.107) @ jammy2026-09-08ubuntu
ubuntulinux-tools-nvidia-tegra-rt-5.15 (5.15.0.1064.64) @ jammy2026-09-08ubuntu
ubuntulinux-tools-ibm-edge (5.15.0.1106.110~20.04.1) @ focal2026-09-08ubuntu
ubuntulinux-tools-aws-lts-24.04 (6.8.0-1061.64+1) @ noble2026-09-08ubuntu
ubuntulinux-tools-azure-lts-24.04 (6.8.0-1063.71) @ noble2026-09-08ubuntu
ubuntulinux-tools-azure-fde-lts-24.04 (6.8.0-1062.69) @ noble2026-09-08ubuntu
ubuntulinux-tools-azure-fips-6.8 (6.8.0-1063.71+fips2) @ noble2026-09-08ubuntu
ubuntulinux-tools-azure-fde-6.8 (6.8.0-1062.69~22.04.1) @ jammy2026-09-08ubuntu
ubuntulinux-tools-oracle-lts-22.04 (5.15.0.1109.105) @ jammy2026-09-08ubuntu
ubuntulinux-tools-azure-fde-lts-22.04 (5.15.0.1117.126) @ jammy2026-09-08ubuntu
ubuntulinux-tools-aws-edge (6.8.0-1061.64~22.04.1) @ jammy2026-09-08ubuntu
ubuntulinux-xilinx-zynqmp (6.8.0.1033.34) @ noble2026-09-08ubuntu
ubuntulinux-virtual-hwe-22.04-edge (6.8.0-136.136~22.04.1) @ jammy2026-09-08ubuntu
ubuntulinux-tools-oracle-edge (5.15.0.1109.115~20.04.1) @ focal2026-09-08ubuntu
ubuntulinux-tools-azure-fips-5.15 (5.15.0.1117.102) @ jammy2026-09-08ubuntu
ubuntulinux-tools-intel-iot-realtime-5.15 (5.15.0.1104.108) @ jammy2026-09-08ubuntu
ubuntulinux-tools-intel-iotg-5.15 (5.15.0.1107.106) @ jammy2026-09-08ubuntu
ubuntulinux-tools-gcp-edge (5.15.0.1112.122~20.04.1) @ focal2026-09-08ubuntu
linuxKernel @ 5.10.253—osv

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(5 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
linux5.10.103-1 ... 5.10.92-2 (53 versions)5.10.257-1—
linux-6.16.1.106-3~deb11u1 ... 6.1.164-1~deb11u1 (16 versions)6.1.170-1~deb11u1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 6.1.99-1 (48 versions)6.1.170-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.85-1~bpo12+1 (17 versions)6.12.85-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 6.19~rc8-1~exp1 (122 versions)6.19.10-1—

All Vendor Advisories

(25)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 5× in last 7d / 29× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 230 total refreshes for this CVE.

  1. 2026-09-13 16:47 UTCEPSS rescore
  2. 2026-09-12 15:01 UTCEPSS rescore
  3. 2026-09-11 14:52 UTCEPSS rescore
  4. 2026-09-10 09:34 UTCEPSS rescore
  5. 2026-09-08 22:00 UTCEPSS rescore
  6. 2026-09-08 09:13 UTCEG score recompute
  7. 2026-09-08 09:13 UTCVendor advisory
  8. 2026-09-08 09:13 UTCGHSA enrichment
  9. 2026-09-07 16:01 UTCEPSS rescore
  10. 2026-09-06 13:47 UTCEPSS rescore
  11. 2026-09-06 13:47 UTCEPSS rescore
  12. 2026-09-04 05:06 UTCEPSS rescore
  13. 2026-09-02 14:11 UTCEPSS rescore
  14. 2026-09-02 11:14 UTCOSV refresh
  15. 2026-09-01 13:53 UTCEPSS rescore
  16. 2026-09-01 04:39 UTCEPSS rescore
  17. 2026-08-30 19:17 UTCEPSS rescore
  18. 2026-08-30 01:22 UTCEPSS rescore
  19. 2026-08-28 21:41 UTCEPSS rescore
  20. 2026-08-27 14:25 UTCEPSS rescore
  21. 2026-08-26 14:46 UTCEPSS rescore
  22. 2026-08-25 13:48 UTCEPSS rescore
  23. 2026-08-23 00:19 UTCEPSS rescore
  24. 2026-08-21 23:49 UTCEPSS rescore
  25. 2026-08-20 22:55 UTCEPSS rescore
Show 75 more
  1. 2026-08-19 17:03 UTCEPSS rescore
  2. 2026-08-18 13:48 UTCEPSS rescore
  3. 2026-08-17 13:47 UTCEPSS rescore
  4. 2026-08-16 14:56 UTCEPSS rescore
  5. 2026-08-16 09:17 UTCEG score recompute
  6. 2026-08-16 09:17 UTCVendor advisory
  7. 2026-08-16 09:17 UTCGHSA enrichment
  8. 2026-08-16 02:14 UTCEPSS rescore
  9. 2026-08-15 01:30 UTCEPSS rescore
  10. 2026-08-14 18:52 UTCVendor advisory
  11. 2026-08-14 18:52 UTCGHSA enrichment
  12. 2026-08-14 05:43 UTCEG score recompute
  13. 2026-08-14 05:43 UTCVendor advisory
  14. 2026-08-14 05:43 UTCGHSA enrichment
  15. 2026-08-13 22:00 UTCEPSS rescore
  16. 2026-08-13 09:56 UTCVendor advisory
  17. 2026-08-13 09:56 UTCGHSA enrichment
  18. 2026-08-12 19:58 UTCEG score recompute
  19. 2026-08-12 19:58 UTCVendor advisory
  20. 2026-08-12 19:58 UTCGHSA enrichment
  21. 2026-08-12 13:50 UTCEPSS rescore
  22. 2026-08-11 20:17 UTCEG score recompute
  23. 2026-08-11 20:17 UTCVendor advisory
  24. 2026-08-11 20:17 UTCGHSA enrichment
  25. 2026-08-11 13:42 UTCEPSS rescore
  26. 2026-08-11 03:26 UTCEG score recompute
  27. 2026-08-11 03:26 UTCVendor advisory
  28. 2026-08-11 03:26 UTCGHSA enrichment
  29. 2026-08-11 00:00 UTCEPSS rescore
  30. 2026-08-10 04:12 UTCVendor advisory
  31. 2026-08-10 04:12 UTCGHSA enrichment
  32. 2026-08-09 16:44 UTCEG score recompute
  33. 2026-08-09 16:44 UTCVendor advisory
  34. 2026-08-09 16:44 UTCGHSA enrichment
  35. 2026-08-09 13:46 UTCEPSS rescore
  36. 2026-08-09 05:14 UTCEG score recompute
  37. 2026-08-09 05:14 UTCVendor advisory
  38. 2026-08-09 05:14 UTCGHSA enrichment
  39. 2026-08-08 16:37 UTCEPSS rescore
  40. 2026-08-08 02:48 UTCEG score recompute
  41. 2026-08-08 02:48 UTCVendor advisory
  42. 2026-08-08 02:48 UTCGHSA enrichment
  43. 2026-08-07 15:21 UTCEG score recompute
  44. 2026-08-07 15:21 UTCVendor advisory
  45. 2026-08-07 15:21 UTCGHSA enrichment
  46. 2026-08-06 13:46 UTCEPSS rescore
  47. 2026-08-06 13:15 UTCVendor advisory
  48. 2026-08-06 13:15 UTCGHSA enrichment
  49. 2026-08-06 00:20 UTCEG score recompute
  50. 2026-08-06 00:20 UTCVendor advisory
  51. 2026-08-06 00:20 UTCGHSA enrichment
  52. 2026-08-05 19:17 UTCEPSS rescore
  53. 2026-08-05 12:41 UTCEG score recompute
  54. 2026-08-05 12:41 UTCVendor advisory
  55. 2026-08-05 12:41 UTCGHSA enrichment
  56. 2026-08-04 15:10 UTCEPSS rescore
  57. 2026-08-04 10:38 UTCEPSS rescore
  58. 2026-08-03 22:39 UTCEG score recompute
  59. 2026-08-03 22:39 UTCVendor advisory
  60. 2026-08-03 22:39 UTCGHSA enrichment
  61. 2026-08-03 10:35 UTCEPSS rescore
  62. 2026-08-03 02:19 UTCVendor advisory
  63. 2026-08-03 02:19 UTCGHSA enrichment
  64. 2026-08-02 14:35 UTCEG score recompute
  65. 2026-08-02 14:35 UTCVendor advisory
  66. 2026-08-02 14:35 UTCGHSA enrichment
  67. 2026-08-02 02:26 UTCEPSS rescore
  68. 2026-08-01 04:15 UTCEPSS rescore
  69. 2026-07-30 01:30 UTCEPSS rescore
  70. 2026-07-27 14:13 UTCEPSS rescore
  71. 2026-07-26 14:54 UTCEPSS rescore
  72. 2026-07-26 14:54 UTCEPSS rescore
  73. 2026-07-26 09:18 UTCEG score recompute
  74. 2026-07-26 09:18 UTCVendor advisory
  75. 2026-07-26 09:18 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-23457?
CVE-2026-23457 is a high vulnerability published on April 3, 2026. In the Linux kernel, the following vulnerability has been resolved: netfilter: nfconntracksip: fix Content-Length u32 truncation in siphelptcp() siphelptcp() parses the SIP Content-Length header with simple_strtoul(), which returns unsigned long, but stores the result in unsigned int clen. On…
When was CVE-2026-23457 disclosed?
CVE-2026-23457 was first published in the National Vulnerability Database on April 3, 2026, with the most recent update on September 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-23457 actively exploited?
CVE-2026-23457 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 63.4% of all scored CVEs.
What is the CVSS score of CVE-2026-23457?
CVE-2026-23457 has a CVSS v4.0 base score of 8.6 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-23457?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-23457, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-23457

Explore →

Is Your Infrastructure Affected by CVE-2026-23457?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs