CVE-2026-3888

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

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, ghsa, secondary
Elevated
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.8Exploit: Elevated riskExposed: 0

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
7.8(medium)
EG Risk
35(Track)
EG Risk 35/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity78% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
31%
KEV
Not listed

Published

March 17, 2026

Last Modified

June 17, 2026

Advisory Details (6)

Auto-updated Jun 4, 2026
🔬 Proof of concept available. Patch available. Sources: ubuntu.
generic

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

http://www.openwall.com/lists/oss-security/2026/03/18/1
ubuntu Patch Available

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

https://ubuntu.com/security/notices/USN-8102-1
ubuntu Patch Available

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
generic

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

https://discourse.ubuntu.com/t/snapd-local-privilege-escalation-cve-2026-3888
generic🟡 PoC Available
https://cdn2.qualys.com/advisory/2026/03/17/snap-confine-systemd-tmpfiles.txt
generic

CVE-2026-3888: Important Snap Flaw Enables Local Privilege Escalation to Root | Qualys

https://blog.qualys.com/vulnerabilities-threat-research/2026/03/17/cve-2026-3888-important-snap-flaw-enables-local-privilege-escalation-to-root

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntuubuntu-snappy-cli (2.61.4ubuntu0.16.04.1+esm2) @ xenial2026-06-11ubuntu
ubuntuubuntu-snappy-cli (2.73+ubuntu24.04.2) @ noble2026-06-11ubuntu

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 rangeFixed inDependents
snapd2.49-1 ... 2.76-1 (40 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
snapd2.57.6-12.57.6-1+deb12u1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
snapd2.68.3-32.68.3-3+deb13u1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
snapd2.68.3-3 ... 2.75.2-2 (10 versions)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 5× in last 7d / 68× 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.

Showing the most recent 100 of 156 total refreshes for this CVE.

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

Publicly available exploits

(4 references)

Working exploit code is in the public domain (4 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCTheCyberGeek/CVE-2026-3888-snap-confine-systemd-tmpfiles-LPE
    First seen Mar 23, 2026
    Open source ↗
  • GitHub PoCnomaisthere/CVE-2026-3888
    First seen Mar 23, 2026

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

    Open source ↗
  • GitHub PoCnetw0rk7/CVE-2026-3888-PoC
    First seen Mar 20, 2026
    Open source ↗
  • GitHub PoCfevar54/CVE-2026-3888-POC-all-from-the-Qualys-platform.
    First seen 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 vulnerability 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 disclosed?
CVE-2026-3888 was first published in the National Vulnerability Database on March 17, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-3888 actively exploited?
CVE-2026-3888 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 68.9% of all scored CVEs.
What is the CVSS score of CVE-2026-3888?
CVE-2026-3888 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2026-3888?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-3888, 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.

Dependency Blast Radius

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