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CVE Record

CVE-2021-39826: Adobe Digital Editions Command Execution Vulnerability

Adobe Digital Editions 4.5.11.187646 (and earlier) are affected by an arbitrary command execution vulnerability. An authenticated attacker could leverage this vulnerability to execute arbitrary commands. User interaction is required to abuse this vulnerability in that a user must open a maliciously crafted .epub file.

HighCVSS 8.6Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

Adobe Digital Editions can run attacker-controlled commands if a user opens a malicious EPUB file. The business risk is endpoint compromise through document handling, especially where employees process ebooks or externally supplied EPUB content.

Executive priority

Treat as high priority where Adobe Digital Editions is present. The required user action lowers internet-scale urgency, but successful exploitation could compromise an endpoint and affect data confidentiality, integrity, and availability.

Technical view

CVE-2021-39826 is a CWE-78 arbitrary command execution issue in Adobe Digital Editions 4.5.11.187646 and earlier. CVSS 3.1 is 8.6 with local attack vector, low complexity, required user interaction, changed scope, and high confidentiality, integrity, and availability impact.

Likely exposure

Exposure is most likely on workstations with Adobe Digital Editions installed, particularly teams handling EPUB files from external parties. The bundle does not identify server-side exposure or affected products beyond Adobe Digital Editions.

Exploitation context

The provided sources do not show CISA KEV listing or active exploitation. Abuse requires a user to open a maliciously crafted EPUB file. Source wording says authenticated attacker, while the CVSS vector says no privileges required.

Researcher notes

Evidence is limited to the CVE record and Adobe bulletin reference. No exploit details, proof of exploitation, or specific fixed version are included in the provided bundle. Validate vendor guidance directly before asserting remediation completeness.

Mitigation direction

  • Inventory Adobe Digital Editions installations and versions.
  • Prioritize Adobe Digital Editions 4.5.11.187646 and earlier.
  • Apply Adobe-provided remediation from APSB21-80 after verification.
  • Limit opening EPUB files from untrusted sources.
  • Consider removing Adobe Digital Editions where not business-required.

Validation and detection

  • Confirm installed Adobe Digital Editions versions on endpoints.
  • Check asset inventory for users handling EPUB files.
  • Review EDR telemetry for suspicious child processes from Digital Editions.
  • Verify remediation status against Adobe APSB21-80.
  • Document any exception where the application remains installed.
Prepared
Confidence
medium
Sources
3

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · medium confidence lookup

CWE-78: Command execution behavior lookup

Command injection weaknesses can lead defenders to review execution techniques and command interpreter telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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cve · low confidence lookup

CVE-2021-39826 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
High
CVSS
8.6 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
0Timeline events
0ADP providers
2Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
8.6CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H1.86Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

8.6High
CVSS 3.1 vector shape for CVE-2021-39826Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
AdobeDigital Editionsunspecified, unspecifiedListed
Weakness

CWE details

CWE-78

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.