CVE-2021-41133

HIGHNVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.8 under NVD CVSS v3. EPSS exploit probability: 0.4%, top 67% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.8Exploit: None knownExposed: 0

A fix is available — apply it.

Flatpak is a system for building, distributing, and running sandboxed desktop applications on Linux. In versions prior to 1.10.4 and 1.12.0, Flatpak apps with direct access to AF_UNIX sockets such as those used by Wayland, Pipewire or pipewire-pulse can trick portals and other host-OS services into treating the Flatpak app as though it was an ordinary, non-sandboxed host-OS process. They can do this by manipulating the VFS using recent mount-related syscalls that are not blocked by Flatpak's denylist seccomp filter, in order to substitute a crafted /.flatpak-info or make that file disappear entirely. Flatpak apps that act as clients for AF_UNIX sockets such as those used by Wayland, Pipewire or pipewire-pulse can escalate the privileges that the corresponding services will believe the Flatpak app has. Note that protocols that operate entirely over the D-Bus session bus (user bus), system bus or accessibility bus are not affected by this. This is due to the use of a proxy process xdg-dbus-proxy, whose VFS cannot be manipulated by the Flatpak app, when interacting with these buses. Patches exist for versions 1.10.4 and 1.12.0, and as of time of publication, a patch for version 1.8.2 is being planned. There are no workarounds aside from upgrading to a patched version.

CVSS v3
8.8
EG Score
8.8(medium)
EG Risk
40(Track)
EG Risk 40/100SSVC: 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
Severity88% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
37%
KEV
Not listed

Published

October 8, 2021

Last Modified

November 21, 2024

Advisory Details (10)

Auto-updated Jul 30, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: github_commit, github.
github Patch Available

CVE-2021-41133: Sandbox bypass via recent VFS-manipulating syscalls · Advisory · flatpak/flatpak · GitHub

https://github.com/flatpak/flatpak/security/advisories/GHSA-67h7-w3jq-vh4q
github_commit Patch Available

commit e26ac7586c39 (flatpak/flatpak)

Patch available: flatpak/flatpak 1.14.5 (contains commit e26ac7586c39)

https://github.com/flatpak/flatpak/commit/e26ac7586c392b5eb35ff4609fe232c52523b2cf
github_commit Patch Available

commit a10f52a7565c (flatpak/flatpak)

Patch available: flatpak/flatpak 1.14.5 (contains commit a10f52a7565c)

https://github.com/flatpak/flatpak/commit/a10f52a7565c549612c92b8e736a6698a53db330
github_commit Patch Available

commit 9766ee05b142 (flatpak/flatpak)

Patch available: flatpak/flatpak 1.14.5 (contains commit 9766ee05b142)

https://github.com/flatpak/flatpak/commit/9766ee05b1425db397d2cf23afd24c7f6146a69f
github_commit Patch Available

commit 89ae9fe74c6d (flatpak/flatpak)

Patch available: flatpak/flatpak 1.14.5 (contains commit 89ae9fe74c6d)

https://github.com/flatpak/flatpak/commit/89ae9fe74c6d445bb1b3a40e568d77cf5de47e48
github_commit Patch Available

commit 4c34815784e9 (flatpak/flatpak)

Patch available: flatpak/flatpak 1.14.5 (contains commit 4c34815784e9)

https://github.com/flatpak/flatpak/commit/4c34815784e9ffda5733225c7d95824f96375e36
github_commit Patch Available

commit 462fca2c666e (flatpak/flatpak)

Patch available: flatpak/flatpak 1.14.5 (contains commit 462fca2c666e)

https://github.com/flatpak/flatpak/commit/462fca2c666e0cd2b60d6d2593a7216a83047aaf
github_commit Patch Available

commit 26b12484eb8a (flatpak/flatpak)

Patch available: flatpak/flatpak 1.14.5 (contains commit 26b12484eb8a)

https://github.com/flatpak/flatpak/commit/26b12484eb8a6219b9e7aa287b298a894b2f34ca
github_commit Patch Available

commit 1330662f33a5 (flatpak/flatpak)

Patch available: flatpak/flatpak 1.14.5 (contains commit 1330662f33a5)

https://github.com/flatpak/flatpak/commit/1330662f33a55e88bfe18e76de28b7922d91a999
generic🔴 Active Exploitation

oss-security - WebKitGTK and WPE WebKit Security Advisory WSA-2021-0006

http://www.openwall.com/lists/oss-security/2021/10/26/9

Vendor Advisories for CVE-2021-41133(1)

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

Patch Availability(5)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntuflatpak-tests (1.10.2-3ubuntu0.1) @ impish2026-05-26ubuntu
redhatflatpak-0:1.0.9-5.el8_12021-11-02redhat
redhatflatpak-0:1.6.2-6.el8_22021-11-02redhat
redhatflatpak-0:1.8.5-4.el8_42021-11-01redhat
redhatflatpak-0:1.0.9-12.el7_92021-11-01redhat

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
flatpak1.10.2-3, 1.10.3-0+deb11u1, 1.10.3-0+deb11u1~bpo11+1, 1.10.5-0+deb11u1~bpo10+11.10.5-0+deb11u1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
flatpak—1.12.1-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
flatpak—1.12.1-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
flatpak—1.12.1-1—

Weakness Classification(1)

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

Additional Vendor Advisories

(4)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

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

Frequently asked(5)

What is CVE-2021-41133?
CVE-2021-41133 is a high vulnerability published on October 8, 2021. Flatpak is a system for building, distributing, and running sandboxed desktop applications on Linux. In versions prior to 1.10.4 and 1.12.0, Flatpak apps with direct access to AFUNIX sockets such as those used by Wayland, Pipewire or pipewire-pulse can trick portals and other host-OS services into…
When was CVE-2021-41133 disclosed?
CVE-2021-41133 was first published in the National Vulnerability Database on October 8, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-41133 actively exploited?
CVE-2021-41133 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 63.4% of all scored CVEs.
What is the CVSS score of CVE-2021-41133?
CVE-2021-41133 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2021-41133?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-41133, 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.

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