CVE-2021-3782

MEDIUMNVD 6.69.8▲
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2022-09-25. NVD baseline CVSS 6.6; sources differ by 3.2.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
6.6
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.6Exploit: NoneExposed: 0

A fix is available — apply it.

An internal reference count is held on the buffer pool, incremented every time a new buffer is created from the pool. The reference count is maintained as an int; on LP64 systems this can cause the reference count to overflow if the client creates a large number of wl_shm buffer objects, or if it can coerce the server to create a large number of external references to the buffer storage. With the reference count overflowing, a use-after-free can be constructed on the wl_shm_pool tracking structure, where values may be incremented or decremented; it may also be possible to construct a limited oracle to leak 4 bytes of server-side memory to the attacking client at a time.

CVSS v3
6.6
EG Score
9.8(medium)
EG Risk
44(Track)
EG Risk 44/100SSVC: 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
Severity98% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
21.9%
KEV
Not listed

Published

September 23, 2022

Last Modified

May 22, 2025

References (2)

Vendor Advisories for CVE-2021-3782(1)

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

Patch Availability(3)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulibwayland-client0 (1.20.0-1ubuntu0.1) @ jammy2026-05-25ubuntu
ubuntulibwayland-client0 (1.12.0-1~ubuntu16.04.3+esm1) @ xenial2026-05-25ubuntu
redhatwayland-0:1.21.0-1.el82023-05-16redhat

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.

Weakness Classification(1)

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

Additional Vendor Advisories

(3)

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 12× in last 7d / 48× 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 109 total refreshes for this CVE.

  1. 2026-07-24 14:15 UTCEPSS rescore
  2. 2026-07-23 14:16 UTCEPSS rescore
  3. 2026-07-23 02:03 UTCEG score recompute
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  49. 2026-06-11 09:09 UTCOSV refresh
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Frequently asked(5)

What is CVE-2021-3782?
CVE-2021-3782 is a medium vulnerability published on September 23, 2022. An internal reference count is held on the buffer pool, incremented every time a new buffer is created from the pool. The reference count is maintained as an int; on LP64 systems this can cause the reference count to overflow if the client creates a large number of wlshm buffer objects, or if it…
When was CVE-2021-3782 disclosed?
CVE-2021-3782 was first published in the National Vulnerability Database on September 23, 2022, with the most recent update on May 22, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-3782 actively exploited?
CVE-2021-3782 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 21.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-3782?
CVE-2021-3782 has a CVSS v3 base score of 6.6 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.8.
How do I remediate CVE-2021-3782?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-3782, 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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