CVE-2023-53635

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2025-10-07. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
5.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.5Exploit: NoneExposed: 0

A fix is available — apply it.

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

netfilter: conntrack: fix wrong ct->timeout value

(struct nf_conn)->timeout is an interval before the conntrack confirmed. After confirmed, it becomes a timestamp.

It is observed that timeout of an unconfirmed conntrack:

  • Set by calling ctnetlink_change_timeout(). As a result,
nfct_time_stamp was wrongly added to ct->timeout twice.
  • Get by calling ctnetlink_dump_timeout(). As a result,
nfct_time_stamp was wrongly subtracted.

Call Trace: dump_stack_lvl ctnetlink_dump_timeout __ctnetlink_glue_build ctnetlink_glue_build __nfqnl_enqueue_packet nf_queue nf_hook_slow ip_mc_output ? __pfx_ip_finish_output ip_send_skb ? __pfx_dst_output udp_send_skb udp_sendmsg ? __pfx_ip_generic_getfrag sock_sendmsg

Separate the 2 cases in:

  • Setting ct->timeout in __nf_ct_set_timeout().
  • Getting ct->timeout in ctnetlink_dump_timeout().

Pablo appends:

Update ctnetlink to set up the timeout _after_ the IPS_CONFIRMED flag is set on, otherwise conntrack creation via ctnetlink breaks.

Note that the problem described in this patch occurs since the introduction of the nfnetlink_queue conntrack support, select a sufficiently old Fixes: tag for -stable kernel to pick up this fix.

CVSS v3
5.5
EG Score
5.5(medium)
EG Risk
—
EPSS
8.8%
KEV
Not listed

Published

October 7, 2025

Last Modified

February 3, 2026

References (4)

Vendor Advisories for CVE-2023-53635(1)

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

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatkernel-0:5.14.0-362.8.1.el9_32023-11-07redhat

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.

Data Freshness Timeline

(refreshed 12× in last 7d / 44× 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.

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

Related CVEs(same vendor)

Frequently asked(5)

What is CVE-2023-53635?
CVE-2023-53635 is a medium vulnerability published on October 7, 2025. In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack: fix wrong ct->timeout value (struct nf_conn)->timeout is an interval before the conntrack confirmed. After confirmed, it becomes a timestamp. It is observed that timeout of an unconfirmed conntrack: Set by…
When was CVE-2023-53635 disclosed?
CVE-2023-53635 was first published in the National Vulnerability Database on October 7, 2025, with the most recent update on February 3, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2023-53635 actively exploited?
CVE-2023-53635 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 8.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2023-53635?
CVE-2023-53635 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2023-53635?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2023-53635, 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.

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