CVE-2026-99064

HIGHPre-NVD 8.18.1
EchelonGraph scoreHIGH confidence

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

Score 8.1 from GitHub Security Advisory (severity: HIGH) published 2026-10-23. A secondary CVSS source baseline 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 3 sources updated this week

Also known asEUVD-2026-108730 (ENISA EUVD) · GHSA-23p2-8f9v-3g5m (GitHub Security Advisories)Source: ENISA EUVD

8.1EG
EchelonGraph verdictPlan mitigationNo fix is confirmed yet: check the vendor's advisory for a fixed release; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 8.1Exploit: None knownExposed services: Not assessed

No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.

The CVE record's CNA (kernel.org) lists Linux versions before 6.10 and 7.3 and later as unaffected. No release containing a fix is confirmed on record.

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

cipso: adjust cached option offsets when removing CIPSO

cipso_v4_skbuff_delattr() removes the CIPSO bytes but does not adjust cached offsets for options that follow them.

For example, with a valid 10-byte CIPSO option followed by a seven-byte RR option, parsing records rr at offset 30. Removing CIPSO moves RR to offset 20, while the cached offset remains 30. Consumers such as ip_forward_options() and __ip_options_echo() then access the wrong bytes; the latter may interpret packet data as the option length and copy it into fixed-size option storage.

Mirror cipso_v4_delopt() and subtract cipso_len from the srr, rr, ts and router_alert offsets when they follow CIPSO. cipso_len is the distance the first memmove() shifts those options. The later header move and network-header reset relocate the bytes and their offset base together.

CVSS v3
8.1
EG Score
8.1HIGHhigh confidence
EG Risk
37
EG Risk 37/100

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)
Severity81% × 45%
Impact severity (EG Severity): CVSS 8.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.5% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: No fix is confirmed yet. Check the vendor's advisory for a fixed release; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule.
EPSS PROB
0.5%
EPSS %ILE
43rd
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 (8.1): severity, escalated by confirmed exploitation. This CVE's 8.1 is its impact severity (EG Severity), not escalated.

EG Severity
8.1 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-30). 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.No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.Each input and its source, and whom BOD 26-04 binds: 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).

No fix is confirmed yet. Check the vendor's advisory for a fixed release; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule.

Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from 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.

No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” 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

October 23, 2026

Last Modified

October 24, 2026

Advisory Details (4)

Auto-updated Oct 24, 2026
No fix on record yet.
Web page

cipso: adjust cached option offsets when removing CIPSO - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/b965977126a90e01825814c859ba4788691eddd3
Web page

cipso: adjust cached option offsets when removing CIPSO - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/6e49d611a9cfbaac927b8fa80ebd4f6b1f37ada0
Web page

cipso: adjust cached option offsets when removing CIPSO - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/6d25ffca055a77787c21a36b66c253f76239411b
Web page

cipso: adjust cached option offsets when removing CIPSO - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2200fe1d6148b78e1b8f00f4b2bd47760015077f

Vendor Advisories for CVE-2026-99064(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 22× 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.

  1. 2026-11-03 16:49 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  2. 2026-11-02 16:46 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  3. 2026-11-01 16:36 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  4. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  5. 2026-10-31 08:30 UTCEG score recompute
  6. 2026-10-31 08:30 UTCGHSA enrichmentGHSA-23p2-8f9v-3g5m · GitHub severity HIGH · GitHub CVSS 8.1
  7. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  8. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  9. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  10. 2026-10-27 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  11. 2026-10-26 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  12. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  13. 2026-10-25 13:46 UTCEG score recompute
  14. 2026-10-24 16:34 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  15. 2026-10-24 14:26 UTCEG score recompute
  16. 2026-10-24 14:26 UTCGHSA enrichmentGHSA-23p2-8f9v-3g5m
  17. 2026-10-24 14:14 UTCEG score recomputeFirst assessed: 8.1 HIGH
  18. 2026-10-24 14:14 UTCGHSA enrichmentGHSA-23p2-8f9v-3g5m
  19. 2026-10-24 14:13 UTCMITRE cvelistV5CVSS v3 → 8.1 · severity → HIGH
  20. 2026-10-23 13:25 UTCNVD update
  21. 2026-10-23 12:48 UTCEG score recompute
  22. 2026-10-23 12:44 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-99064?
CVE-2026-99064 is a high-severity vulnerability; its CVE record was published on October 23, 2026. In the Linux kernel, the following vulnerability has been resolved: cipso: adjust cached option offsets when removing CIPSO cipso_v4_skbuff_delattr() removes the CIPSO bytes but does not adjust cached offsets for options that follow them. For example, with a valid 10-byte CIPSO option followed by a…
When was the CVE record for CVE-2026-99064 published?
The CVE record for CVE-2026-99064 was published on October 23, 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 24, 2026; the record at its source may have been updated since.
Is CVE-2026-99064 actively exploited?
CVE-2026-99064 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (43rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-99064?
CVE-2026-99064 has a CVSS base score of 8.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-99064?
No fix for CVE-2026-99064 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The CVE record's CNA (kernel.org) lists Linux versions before 6.10 and 7.3 and later as unaffected. No release containing a fix is confirmed on record. The vendor advisories EchelonGraph has for CVE-2026-99064 are linked in the Vendor Advisories panel on this page.

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