CVE-2026-90954

HIGHPre-NVD 7.87.8
EchelonGraph scoreHIGH confidence

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

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-10-14. 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-2026-100951 (ENISA EUVD) · GHSA-68qr-37mv-cwhv (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.

A flaw was found in BusyBox's dpkg-deb archive extraction. The ar archive handler flushes deferred symlinks after each archive member, unlike the tar, cpio, and unzip handlers which flush once after the last member. A specially crafted .deb archive with two data.tar members can exploit this ordering: the first member declares a symlink pointing to an absolute path (e.g., '/'), which is deferred as unsafe but flushed after the first member. The second member declares a regular file whose path traverses the now-live symlink, resulting in a file being written outside the intended extraction directory. This could allow an attacker to write arbitrary files to arbitrary locations when a user extracts a crafted .deb package.

CVSS v3
7.8
EG Score
7.8HIGHhigh 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
14th
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

October 14, 2026

Last Modified

October 19, 2026

Advisory Details (2)

Auto-updated Oct 14, 2026
Patch available. Sources: redhat.
Red Hat

2533007 – (CVE-2026-90954) CVE-2026-90954 busybox: busybox: dpkg-deb extraction-root escape via per-ar-member deferred symlink flush

https://bugzilla.redhat.com/show_bug.cgi?id=2533007
Red HatMentions a patch (unverified)

CVE-2026-90954 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a

https://access.redhat.com/security/cve/CVE-2026-90954

Vendor Advisories for CVE-2026-90954(2)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 28× 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. 2026-10-27 18:37 UTCEG score recompute
  2. 2026-10-27 18:37 UTCVendor advisory
  3. 2026-10-27 18:37 UTCGHSA enrichmentGHSA-68qr-37mv-cwhv · GitHub severity HIGH · GitHub CVSS 7.8
  4. 2026-10-27 16:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  5. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  6. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  7. 2026-10-25 13:51 UTCEG score recompute
  8. 2026-10-24 16:34 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  9. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  10. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  11. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  12. 2026-10-20 16:34 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  13. 2026-10-19 20:31 UTCEG score recompute
  14. 2026-10-19 20:31 UTCGHSA enrichmentGHSA-68qr-37mv-cwhv · GitHub severity HIGH · GitHub CVSS 7.8
  15. 2026-10-19 19:23 UTCEG score recompute
  16. 2026-10-19 19:23 UTCGHSA enrichmentGHSA-68qr-37mv-cwhv · GitHub severity HIGH · GitHub CVSS 7.8
  17. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  18. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  19. 2026-10-18 03:00 UTCEG score recompute
  20. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  21. 2026-10-16 16:45 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  22. 2026-10-15 16:47 UTCEG score recompute
  23. 2026-10-15 16:47 UTCGHSA enrichmentGHSA-68qr-37mv-cwhv · GitHub severity HIGH · GitHub CVSS 7.8
  24. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  25. 2026-10-14 16:34 UTCEPSS rescoreEPSS 0.2% · 8th percentile
Show 3 more
  1. 2026-10-14 10:28 UTCEG score recompute
  2. 2026-10-14 10:05 UTCEG score recomputeFirst assessed: 7.8 HIGH
  3. 2026-10-14 10:04 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-90954?
CVE-2026-90954 is a high-severity vulnerability; its CVE record was published on October 14, 2026. A flaw was found in BusyBox's dpkg-deb archive extraction. The ar archive handler flushes deferred symlinks after each archive member, unlike the tar, cpio, and unzip handlers which flush once after the last member. A specially crafted .deb archive with two data.tar members can exploit this…
When was CVE-2026-90954 made public?
CVE-2026-90954 was made public on October 14, 2026: that is the date its CVE record's CNA, Red Hat, Inc., gives for when the vulnerability was made public. The CVE record itself was published on October 14, 2026. 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-2026-90954 actively exploited?
CVE-2026-90954 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (14th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-90954?
CVE-2026-90954 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-2026-90954?
A fix for CVE-2026-90954 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-90954 are linked in the Vendor Advisories panel on this page.

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