CVE-2026-53366

HIGHPre-NVD 7.87.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-16. A secondary CVSS source baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 4 sources updated this week

Also known asEUVD-2026-44868 (ENISA EUVD) · GHSA-r67c-r6r6-mj6m (GitHub Security Advisories)Source: ENISA EUVD

7.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 7.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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

ipv4: account for fraggap on the paged allocation path

In __ip_append_data(), when the paged-allocation branch is taken, alloclen and pagedlen are computed as

alloclen = fragheaderlen + transhdrlen; pagedlen = datalen - transhdrlen;

datalen already includes fraggap, but the fraggap bytes carried over from the previous skb are copied into the new skb's linear area at offset transhdrlen by the subsequent skb_copy_and_csum_bits(). The linear area is therefore undersized by fraggap bytes while pagedlen is overstated by the same amount.

The non-paged branch sets alloclen to fraglen, which already accounts for fraggap because datalen does. Bring the paged branch in line by adding fraggap to alloclen and subtracting it from pagedlen.

After this adjustment, copy no longer collapses to -fraggap on the paged path, so remove the stale comment describing that old arithmetic.

CVSS v3
7.8
EG Score
7.8HIGHmedium confidence
EG Risk
35
EG Risk 35/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity78% × 45%
Impact severity (EG Severity): CVSS 7.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.2% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
6th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.8): severity, escalated by confirmed exploitation. This CVE's 7.8 is its impact severity (EG Severity), not escalated.

EG Severity
7.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-27). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

July 16, 2026

Last Modified

October 19, 2026

Advisory Details (5)

Auto-updated Jul 18, 2026
Patch available.
Web page

ipv4: account for fraggap on the paged allocation path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/eca856950f7cb1a221e02b99d758409f2c5cec42
Web page

ipv4: account for fraggap on the paged allocation path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c04d9ece23deb9e26c19f9ca215e98b3295aa1bb
Web page

ipv4: account for fraggap on the paged allocation path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/77798d7be6ef71e72fb6fc8a2901bf74ebc9706f
Web page

ipv4: account for fraggap on the paged allocation path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a9c24eda24bd15f432e37824e6fc440977cb241c
Web page

ipv4: account for fraggap on the paged allocation path - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ce494707a9c07f27c219ca67f3e138061f53d9b3

Patch Availability(17)

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

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
linux-6.16.1.106-3~deb11u1 ... 6.1.176-1~deb11u1 (21 versions)
  • every version up to 6.1.177-1~deb11u1: fixed in 6.1.177-1~deb11u1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.106-1 ... 6.1.99-1 (54 versions)
  • every version up to 6.1.177-1: fixed in 6.1.177-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.38-1 ... 6.12.95-1~bpo12+1 (29 versions)
  • every version up to 6.12.95-1: fixed in 6.12.95-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.1~rc7-1~exp1 (157 versions)
  • every version up to 7.1.3-1: fixed in 7.1.3-1
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(14)

Data Freshness Timeline

(refreshed 11× in last 7d / 51× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 325 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 225 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  2. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  3. 2026-10-27 17:38 UTCEG score recompute
  4. 2026-10-27 17:38 UTCVendor advisory
  5. 2026-10-27 17:37 UTCGHSA enrichmentGHSA-r67c-r6r6-mj6m · GitHub severity HIGH · GitHub CVSS 7.8
  6. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  7. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  8. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  9. 2026-10-25 14:20 UTCEG score recompute
  10. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  11. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  12. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  13. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  14. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  15. 2026-10-19 20:21 UTCEG score recompute
  16. 2026-10-19 20:21 UTCVendor advisory
  17. 2026-10-19 20:20 UTCGHSA enrichmentGHSA-r67c-r6r6-mj6m · GitHub severity HIGH · GitHub CVSS 7.8
  18. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  19. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  20. 2026-10-18 03:31 UTCEG score recompute
  21. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  22. 2026-10-16 17:06 UTCEG score recompute
  23. 2026-10-16 17:06 UTCVendor advisory
  24. 2026-10-16 17:05 UTCGHSA enrichmentGHSA-r67c-r6r6-mj6m · GitHub severity HIGH · GitHub CVSS 7.8
  25. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.2% · 6th percentile
Show 75 more
  1. 2026-10-16 15:41 UTCEG score recompute
  2. 2026-10-16 15:41 UTCVendor advisory
  3. 2026-10-16 15:41 UTCGHSA enrichmentGHSA-r67c-r6r6-mj6m · GitHub severity HIGH · GitHub CVSS 7.8
  4. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  5. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  6. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  7. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  8. 2026-10-12 15:57 UTCEG score recompute
  9. 2026-10-11 19:40 UTCEG score recompute
  10. 2026-10-11 16:55 UTCEG score recompute
  11. 2026-10-11 14:19 UTCEG score recompute
  12. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  13. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  14. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  15. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  16. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  17. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  18. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  19. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  20. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  21. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  22. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  23. 2026-10-01 11:30 UTCEG score recompute
  24. 2026-10-01 11:30 UTCVendor advisory
  25. 2026-10-01 11:30 UTCGHSA enrichmentGHSA-r67c-r6r6-mj6m · GitHub severity HIGH · GitHub CVSS 7.8
  26. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  27. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  28. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  29. 2026-09-28 08:39 UTCEG score recompute
  30. 2026-09-28 08:39 UTCVendor advisory
  31. 2026-09-28 08:39 UTCGHSA enrichmentGHSA-r67c-r6r6-mj6m · GitHub severity HIGH · GitHub CVSS 7.8
  32. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  33. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  34. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  35. 2026-09-24 08:38 UTCEG score recompute
  36. 2026-09-24 08:38 UTCVendor advisory
  37. 2026-09-24 08:38 UTCGHSA enrichmentGHSA-r67c-r6r6-mj6m · GitHub severity HIGH · GitHub CVSS 7.8
  38. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  39. 2026-09-23 03:09 UTCEG score recompute
  40. 2026-09-23 03:09 UTCVendor advisory
  41. 2026-09-23 03:09 UTCGHSA enrichmentGHSA-r67c-r6r6-mj6m · GitHub severity HIGH · GitHub CVSS 7.8
  42. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  43. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  44. 2026-09-18 04:40 UTCEG score recompute
  45. 2026-09-18 04:40 UTCVendor advisory
  46. 2026-09-18 04:40 UTCGHSA enrichmentGHSA-r67c-r6r6-mj6m · GitHub severity HIGH · GitHub CVSS 7.8
  47. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  48. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  49. 2026-09-14 12:21 UTCVendor advisory
  50. 2026-09-14 12:21 UTCGHSA enrichmentGHSA-r67c-r6r6-mj6m · GitHub severity HIGH · GitHub CVSS 7.8
  51. 2026-09-13 23:10 UTCEG score recompute
  52. 2026-09-13 23:10 UTCVendor advisory
  53. 2026-09-13 23:10 UTCGHSA enrichmentGHSA-r67c-r6r6-mj6m · GitHub severity HIGH · GitHub CVSS 7.8
  54. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  55. 2026-09-13 07:10 UTCEG score recompute
  56. 2026-09-13 07:10 UTCVendor advisory
  57. 2026-09-13 07:10 UTCGHSA enrichmentGHSA-r67c-r6r6-mj6m · GitHub severity HIGH · GitHub CVSS 7.8
  58. 2026-09-12 12:51 UTCVendor advisory
  59. 2026-09-12 12:50 UTCGHSA enrichmentGHSA-r67c-r6r6-mj6m · GitHub severity HIGH · GitHub CVSS 7.8
  60. 2026-09-11 21:42 UTCEG score recompute
  61. 2026-09-11 21:42 UTCVendor advisory
  62. 2026-09-11 21:42 UTCGHSA enrichmentGHSA-r67c-r6r6-mj6m · GitHub severity HIGH · GitHub CVSS 7.8
  63. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  64. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  65. 2026-09-08 00:37 UTCEG score recompute
  66. 2026-09-08 00:37 UTCVendor advisory
  67. 2026-09-08 00:37 UTCGHSA enrichmentGHSA-r67c-r6r6-mj6m · GitHub severity HIGH · GitHub CVSS 7.8
  68. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  69. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  70. 2026-09-06 13:27 UTCVendor advisory
  71. 2026-09-06 13:27 UTCGHSA enrichmentGHSA-r67c-r6r6-mj6m · GitHub severity HIGH · GitHub CVSS 7.8
  72. 2026-09-05 20:43 UTCEG score recompute
  73. 2026-09-05 20:43 UTCVendor advisory
  74. 2026-09-05 20:43 UTCGHSA enrichmentGHSA-r67c-r6r6-mj6m · GitHub severity HIGH · GitHub CVSS 7.8
  75. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.2% · 6th percentile

Frequently asked(5)

What is CVE-2026-53366?
CVE-2026-53366 is a high-severity vulnerability; its CVE record was published on July 16, 2026. In the Linux kernel, the following vulnerability has been resolved: ipv4: account for fraggap on the paged allocation path In ipappenddata(), when the paged-allocation branch is taken, alloclen and pagedlen are computed as alloclen = fragheaderlen + transhdrlen; pagedlen = datalen - transhdrlen;…
When was the CVE record for CVE-2026-53366 published?
The CVE record for CVE-2026-53366 was published on July 16, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 19, 2026; the record at its source may have been updated since.
Is CVE-2026-53366 actively exploited?
CVE-2026-53366 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (6th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-53366?
CVE-2026-53366 has a CVSS base score of 7.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-53366?
A fix for CVE-2026-53366 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-53366 are linked in the Vendor Advisories panel on this page.

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