CVE-2026-3888

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 2026-03-17. 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 weekWeaponized

Also known asEUVD-2026-12570 (ENISA EUVD) · GHSA-grpw-jgrw-ccqr (GitHub Security Advisories)Source: ENISA EUVD

7.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • Public exploit code is available (Metasploit, other public proof-of-concept code)
CISA-KEV: Not listedEPSS PROB: 1.4%CVSS: 7.8Exploit: Metasploit · other public PoCExposed services: Not assessed

A fix is available — apply it.

Local privilege escalation in snapd on Linux allows local attackers to get root privilege by re-creating snap's private /tmp directory when systemd-tmpfiles is configured to automatically clean up this directory. This issue affects Ubuntu 16.04 LTS, 18.04 LTS, 20.04 LTS, 22.04 LTS, and 24.04 LTS.

CVSS v3
7.8
EG Score
7.8HIGHmedium confidence
EG Risk
61
EG Risk 61/100

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.
Exploitation65% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 2 (Weaponized): a constant, not a probability.
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
1.4%
EPSS %ILE
72nd
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
1.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-29). 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, 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).

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.

The score's inputs: 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

March 17, 2026

Last Modified

June 17, 2026

Advisory Details (6)

Auto-updated Jun 4, 2026
Patch available. Sources: ubuntu.
Web page

oss-security - Re: snap-confine + systemd-tmpfiles = root (CVE-2026-3888)

http://www.openwall.com/lists/oss-security/2026/03/18/1
UbuntuMentions a patch (unverified)

USN-8102-1: snapd vulnerability | Ubuntu security notices | Ubuntu

https://ubuntu.com/security/notices/USN-8102-1
UbuntuMentions a patch (unverified)

CVE-2026-3888 | Ubuntu

Affected: Ubuntu 16.04 LTS, 18.04 LTS, 20.04 LTS, 22.04 LTS, and

https://ubuntu.com/security/CVE-2026-3888
Web page

Snapd - Local Privilege Escalation (CVE-2026-3888) - Security - Ubuntu Community Hub

https://discourse.ubuntu.com/t/snapd-local-privilege-escalation-cve-2026-3888

Patch Availability(2)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntuubuntu-snappy-cli (2.73+ubuntu24.04.2) @ noble2026-10-30ubuntu
ubuntuubuntu-snappy-cli (2.67.1+20.04ubuntu1~esm1) @ focal2026-10-30ubuntu

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
snapd2.49-1 ... 2.76-1 (40 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
snapd2.57.6-1
  • every version up to 2.57.6-1+deb12u1: fixed in 2.57.6-1+deb12u1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
snapd2.68.3-3
  • every version up to 2.68.3-3+deb13u1: fixed in 2.68.3-3+deb13u1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
snapd2.68.3-3 ... 2.75.2-2 (10 versions)
  • every version up to 2.76-1: fixed in 2.76-1
—

Weakness Classification(1)

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

All Vendor Advisories

(2)

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 10× in last 7d / 45× 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 99 of 230 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. 1 repeat row among the latest 100 is merged into the row it repeats. The 131 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:34 UTCEPSS rescoreEPSS 1.4% · 72nd percentile
  2. 2026-10-31 16:32 UTCEPSS rescoreEPSS 1.4% · 72nd percentile
  3. 2026-10-30 16:34 UTCEPSS rescoreEPSS 1.4% · 72nd percentile
  4. 2026-10-30 16:05 UTCEG score recompute
  5. 2026-10-30 16:05 UTCVendor advisory
  6. 2026-10-30 16:05 UTCGHSA enrichmentGHSA-grpw-jgrw-ccqr · GitHub severity HIGH · GitHub CVSS 7.8
  7. 2026-10-29 16:33 UTCEPSS rescoreEPSS 1.4% · 72nd percentile
  8. 2026-10-28 16:32 UTCEPSS rescoreEPSS 1.4% · 72nd percentile
  9. 2026-10-27 16:31 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  10. 2026-10-26 16:31 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  11. 2026-10-25 16:32 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  12. 2026-10-25 14:32 UTCEG score recompute
  13. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  14. 2026-10-24 03:37 UTCEG score recompute
  15. 2026-10-24 03:37 UTCVendor advisory
  16. 2026-10-24 03:37 UTCGHSA enrichmentGHSA-grpw-jgrw-ccqr · GitHub severity HIGH · GitHub CVSS 7.8
  17. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  18. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  19. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  20. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  21. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  22. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  23. 2026-10-18 03:44 UTCEG score recompute
  24. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  25. 2026-10-17 15:09 UTCEG score recompute
Show 74 more
  1. 2026-10-17 15:08 UTCGHSA enrichmentGHSA-grpw-jgrw-ccqr · GitHub severity HIGH · GitHub CVSS 7.8
  2. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  3. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  4. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  5. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  6. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  7. 2026-10-12 16:10 UTCEG score recompute
  8. 2026-10-11 19:52 UTCEG score recompute
  9. 2026-10-11 17:06 UTCEG score recompute
  10. 2026-10-11 14:32 UTCEG score recompute
  11. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  12. 2026-10-11 09:44 UTCOSV refresh
  13. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  14. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  15. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  16. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  17. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  18. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  19. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  20. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  21. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  22. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  23. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  24. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  25. 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  26. 2026-09-21 22:16 UTCOSV refresh
  27. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  28. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  29. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  30. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  31. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  32. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  33. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  34. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  35. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  36. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  37. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  38. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  39. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  40. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  41. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  42. 2026-09-02 18:08 UTCOSV refresh
  43. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  44. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  45. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  46. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  47. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  48. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  49. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  50. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  51. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  52. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  53. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  54. 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  55. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  56. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  57. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  58. 2026-08-16 11:22 UTCEG score recompute
  59. 2026-08-16 11:22 UTCVendor advisory
  60. 2026-08-16 11:22 UTCGHSA enrichmentGHSA-grpw-jgrw-ccqr · GitHub severity HIGH · GitHub CVSS 7.8
  61. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  62. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  63. 2026-08-14 19:58 UTCVendor advisory
  64. 2026-08-14 19:58 UTCGHSA enrichmentGHSA-grpw-jgrw-ccqr · GitHub severity HIGH · GitHub CVSS 7.8
  65. 2026-08-14 07:28 UTCEG score recompute
  66. 2026-08-14 07:28 UTCVendor advisory
  67. 2026-08-14 07:28 UTCGHSA enrichmentGHSA-grpw-jgrw-ccqr · GitHub severity HIGH · GitHub CVSS 7.8
  68. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  69. 2026-08-12 22:16 UTCEG score recompute
  70. 2026-08-12 22:16 UTCVendor advisory
  71. 2026-08-12 22:16 UTCGHSA enrichmentGHSA-grpw-jgrw-ccqr · GitHub severity HIGH · GitHub CVSS 7.8
  72. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  73. 2026-08-11 21:34 UTCEG score recompute
  74. 2026-08-11 21:34 UTCVendor advisory

Publicly available exploits

(6 references)

Public exploit code is referenced for this CVE (1 Metasploit module, 5 GitHub PoCs). Defenders should treat patch urgency accordingly.

  • Metasploitexploit/linux/local/cve_2026_3888✓ verified
    Published Oct 8, 2026

    Local Privilege Escalation in snapd

    Open source ↗
  • GitHub PoCnoambouillet/CVE-2026-3888
    Published Mar 23, 2026

    Linux LPE via snap-confine + systemd-tmpfiles, explained in depth

    Open source ↗
  • GitHub PoCnomaisthere/CVE-2026-3888
    Published Mar 23, 2026

    Linux LPE via snap-confine + systemd-tmpfiles, explained in depth

    Open source ↗
  • GitHub PoCTheCyberGeek/CVE-2026-3888-snap-confine-systemd-tmpfiles-LPE
    Published Mar 23, 2026
    Open source ↗
  • GitHub PoCnetw0rk7/CVE-2026-3888-PoC
    Published Mar 20, 2026
    Open source ↗
  • GitHub PoCfevar54/CVE-2026-3888-POC-all-from-the-Qualys-platform.
    Published Mar 18, 2026

    This script demonstrates a race condition vulnerability in snapd that allows a local, unprivileged user to gain root privileges. The exploit works by recreating snap's private /tmp directory after it's cleaned up by systemd-tmpfiles, and tricking snap-confine into bind-mounting malicious files into the snap's sandbox.

    Open source ↗

Frequently asked(5)

What is CVE-2026-3888?
CVE-2026-3888 is a high-severity vulnerability; its CVE record was published on March 17, 2026. Local privilege escalation in snapd on Linux allows local attackers to get root privilege by re-creating snap's private /tmp directory when systemd-tmpfiles is configured to automatically clean up this directory. This issue affects Ubuntu 16.04 LTS, 18.04 LTS, 20.04 LTS, 22.04 LTS, and 24.04 LTS.
When was CVE-2026-3888 made public?
CVE-2026-3888 was made public on March 17, 2026: that is the date its CVE record's CNA, Canonical Ltd., gives for when the vulnerability was made public. The CVE record itself was published on March 17, 2026. EchelonGraph's copy of the record carries a last-modified date of June 17, 2026; the record at its source may have been updated since.
Is CVE-2026-3888 actively exploited?
CVE-2026-3888 is not currently on CISA's Known Exploited Vulnerabilities catalog. EchelonGraph's EG-KEV model places it in Tier 2 (Weaponized), which is not evidence of exploitation: a Metasploit module exists for it. EchelonGraph does not test whether exploit code works. FIRST EPSS estimates a 1.4% probability of exploitation in the next 30 days (72nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-3888?
CVE-2026-3888 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-2026-3888?
A fix for CVE-2026-3888 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

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