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.
CVE-2021-41133
“—” beside the score: it is equal to NVD's CVSS score.
This high-severity CVE scores 8.8 under NVD CVSS v3. EPSS exploit probability: 0.4% (36th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 8.8
- EG Score
- 8.8HIGHmedium confidence
- EG Risk
- 40EG Risk 40/100
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)Severity88% × 45%Impact severity (EG Severity): CVSS 8.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation0.4% × 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
- 0.4%
- EPSS %ILE
- 36th
- 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 (8.8): severity, escalated by confirmed exploitation. This CVE's 8.8 is its impact severity (EG Severity), not escalated.
- EG Severity
- 8.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
- EG Likelihood
- 0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-20). 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 8, 2021
Last Modified
November 21, 2024
Advisory Details (10)
Auto-updated Jul 30, 2026CVE-2021-41133: Sandbox bypass via recent VFS-manipulating syscalls · Advisory · flatpak/flatpak · GitHub
https://github.com/flatpak/flatpak/security/advisories/GHSA-67h7-w3jq-vh4qcommit e26ac7586c39 (flatpak/flatpak)
Patch available: flatpak/flatpak 1.14.5 (contains commit e26ac7586c39)
https://github.com/flatpak/flatpak/commit/e26ac7586c392b5eb35ff4609fe232c52523b2cfcommit a10f52a7565c (flatpak/flatpak)
Patch available: flatpak/flatpak 1.14.5 (contains commit a10f52a7565c)
https://github.com/flatpak/flatpak/commit/a10f52a7565c549612c92b8e736a6698a53db330commit 9766ee05b142 (flatpak/flatpak)
Patch available: flatpak/flatpak 1.14.5 (contains commit 9766ee05b142)
https://github.com/flatpak/flatpak/commit/9766ee05b1425db397d2cf23afd24c7f6146a69fcommit 89ae9fe74c6d (flatpak/flatpak)
Patch available: flatpak/flatpak 1.14.5 (contains commit 89ae9fe74c6d)
https://github.com/flatpak/flatpak/commit/89ae9fe74c6d445bb1b3a40e568d77cf5de47e48commit 4c34815784e9 (flatpak/flatpak)
Patch available: flatpak/flatpak 1.14.5 (contains commit 4c34815784e9)
https://github.com/flatpak/flatpak/commit/4c34815784e9ffda5733225c7d95824f96375e36commit 462fca2c666e (flatpak/flatpak)
Patch available: flatpak/flatpak 1.14.5 (contains commit 462fca2c666e)
https://github.com/flatpak/flatpak/commit/462fca2c666e0cd2b60d6d2593a7216a83047aafcommit 26b12484eb8a (flatpak/flatpak)
Patch available: flatpak/flatpak 1.14.5 (contains commit 26b12484eb8a)
https://github.com/flatpak/flatpak/commit/26b12484eb8a6219b9e7aa287b298a894b2f34cacommit 1330662f33a5 (flatpak/flatpak)
Patch available: flatpak/flatpak 1.14.5 (contains commit 1330662f33a5)
https://github.com/flatpak/flatpak/commit/1330662f33a55e88bfe18e76de28b7922d91a999oss-security - WebKitGTK and WPE WebKit Security Advisory WSA-2021-0006
http://www.openwall.com/lists/oss-security/2021/10/26/9Vendor 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 / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| ubuntu | flatpak-tests (1.10.2-1ubuntu1.1) @ hirsute | 2026-10-21 | ubuntu |
| redhat | flatpak-0:1.0.9-5.el8_1 | 2021-11-02 | redhat |
| redhat | flatpak-0:1.6.2-6.el8_2 | 2021-11-02 | redhat |
| redhat | flatpak-0:1.8.5-4.el8_4 | 2021-11-01 | redhat |
| redhat | flatpak-0:1.0.9-12.el7_9 | 2021-11-01 | redhat |
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)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| flatpak | 1.10.2-3, 1.10.3-0+deb11u1, 1.10.3-0+deb11u1~bpo11+1, 1.10.5-0+deb11u1~bpo10+1 |
| — |
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| flatpak | — |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| flatpak | — |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| flatpak | — |
| — |
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 11× in last 7d / 38× 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 95 of 204 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. 5 repeat rows among the latest 100 are merged into the row they repeat. The 109 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-10-23 16:28 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-22 16:29 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-21 16:28 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-21 09:00 UTCEG score recompute
- 2026-10-21 09:00 UTCVendor advisory
- 2026-10-20 16:28 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-19 16:28 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-18 16:28 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-18 08:54 UTCEG score recompute
- 2026-10-17 20:55 UTCOSV refresh
- 2026-10-17 16:29 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-16 16:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-15 16:28 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-14 16:29 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-13 16:28 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-12 19:10 UTCEG score recompute
- 2026-10-12 16:30 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-11 23:35 UTCEG score recompute
- 2026-10-11 13:44 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-10 19:56 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-09 20:04 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-08 16:40 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-07 23:45 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-06 15:14 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-05 17:40 UTCEPSS rescoreEPSS 0.4% · 35th percentile
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- 2026-10-04 23:19 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-03 14:22 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-02 16:23 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-01 19:46 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-30 15:41 UTCEG score recompute
- 2026-09-30 15:00 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-29 15:15 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-28 13:47 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-27 13:41 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-26 15:54 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-26 00:21 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-25 15:45 UTCOSV refresh
- 2026-09-24 14:00 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-23 13:44 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-09-22 14:44 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-09-21 20:28 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-09-20 20:13 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-09-19 15:38 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-09-18 19:23 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-09-17 19:23 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-09-16 14:05 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-09-15 03:06 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-12 14:57 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-11 14:49 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-11 09:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-08 21:56 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-07 15:58 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-06 13:45 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-06 06:22 UTCOSV refresh
- 2026-09-05 15:25 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-04 13:57 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-04 05:03 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-02 14:09 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-01 13:50 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-01 03:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-30 19:14 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-30 01:19 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-28 21:37 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-27 14:22 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-26 14:43 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-25 13:46 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-24 14:13 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-23 00:16 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-21 23:46 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-20 22:52 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-19 17:26 UTCOSV refresh
- 2026-08-19 17:01 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-18 13:45 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-17 13:44 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-16 14:53 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-16 02:11 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-15 01:27 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-13 21:57 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-12 13:48 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-11 13:38 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-09 13:44 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-08-08 16:33 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-08-07 16:24 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-08-06 13:44 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-08-05 19:14 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-08-04 12:57 UTCOSV refresh
- 2026-08-04 10:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-08-03 10:33 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-08-02 02:24 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-08-01 04:13 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-07-30 16:25 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-07-30 01:28 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-07-28 15:33 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-07-26 14:52 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-07-25 14:15 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
Related CVEs(same product + same CWE)
Same product
10 shownDebian:11:flatpak
Frequently asked(5)
What is CVE-2021-41133?
When was the CVE record for CVE-2021-41133 published?
Is CVE-2021-41133 actively exploited?
What is the CVSS score of CVE-2021-41133?
How do I remediate CVE-2021-41133?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-41133
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