CVE-2021-39840

HIGHNVD 7.88.2▲
EchelonGraph scoreHIGH confidence

Score elevated to 8.2 because EPSS predicts 50% probability of exploitation within the next 30 days (top 1.2% of all CVEs). NVD baseline CVSS 7.8 retained for reference. Confidence: see factors.

Triggered by: EPSS exploit prediction ≥85%
Sources: epss, nvd
Elevated
8.2EG
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 51%
CISA-KEV: Not listedEPSS PROB: 51%CVSS: 7.8Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Acrobat Reader DC versions 2021.005.20060 (and earlier), 2020.004.30006 (and earlier) and 2017.011.30199 (and earlier) are affected by a use-after-free vulnerability when processing AcroForms that could result in arbitrary code execution in the context of the current user. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.

CVSS v3
7.8
EG Score
8.2(high)
EG Risk
61(Track)
EG Risk 61/100SSVC: 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
Severity82% × 45%
Exploitation50% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
51%
EPSS %ILE
99%
KEV
Not listed

Published

September 29, 2021

Last Modified

November 21, 2024

References (2)

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 35× 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.

  1. 2026-07-26 14:52 UTCEPSS rescore
  2. 2026-07-26 14:52 UTCEPSS rescore
  3. 2026-07-25 14:15 UTCEPSS rescore
  4. 2026-07-24 14:15 UTCEPSS rescore
  5. 2026-07-23 14:16 UTCEPSS rescore
  6. 2026-07-23 02:04 UTCEG score recompute▲ 0.40
  7. 2026-07-22 22:50 UTCEG score recompute
  8. 2026-07-22 14:06 UTCEPSS rescore
  9. 2026-07-21 15:22 UTCEPSS rescore
  10. 2026-07-21 15:22 UTCEPSS rescore
  11. 2026-07-20 17:05 UTCEPSS rescore
  12. 2026-07-19 02:27 UTCEPSS rescore
  13. 2026-07-16 17:00 UTCEPSS rescore
  14. 2026-07-16 17:00 UTCEPSS rescore
  15. 2026-07-15 16:55 UTCEPSS rescore
  16. 2026-07-15 16:55 UTCEPSS rescore
  17. 2026-07-15 01:58 UTCEPSS rescore
  18. 2026-07-13 22:27 UTCEPSS rescore
  19. 2026-07-13 22:27 UTCEPSS rescore
  20. 2026-07-13 06:11 UTCEPSS rescore
  21. 2026-07-13 06:11 UTCEPSS rescore
  22. 2026-07-12 05:44 UTCEPSS rescore
  23. 2026-07-11 08:25 UTCEPSS rescore
  24. 2026-07-11 08:25 UTCEPSS rescore
  25. 2026-07-09 19:07 UTCEPSS rescore
Show 57 more
  1. 2026-07-08 15:12 UTCEPSS rescore
  2. 2026-07-07 13:43 UTCEPSS rescore
  3. 2026-07-04 06:29 UTCEPSS rescore
  4. 2026-07-04 06:29 UTCEPSS rescore
  5. 2026-07-02 16:57 UTCEPSS rescore
  6. 2026-07-01 15:04 UTCEPSS rescore
  7. 2026-06-28 04:54 UTCEPSS rescore
  8. 2026-06-28 04:54 UTCEPSS rescore
  9. 2026-06-27 03:06 UTCEPSS rescore
  10. 2026-06-27 03:06 UTCEPSS rescore
  11. 2026-06-25 13:48 UTCEPSS rescore
  12. 2026-06-25 13:48 UTCEPSS rescore
  13. 2026-06-23 21:31 UTCEPSS rescore
  14. 2026-06-23 21:31 UTCEPSS rescore
  15. 2026-06-21 01:58 UTCEPSS rescore
  16. 2026-06-21 01:58 UTCEPSS rescore
  17. 2026-06-19 19:24 UTCEPSS rescore
  18. 2026-06-19 19:24 UTCEPSS rescore
  19. 2026-06-18 17:51 UTCEPSS rescore
  20. 2026-06-18 17:51 UTCEPSS rescore
  21. 2026-06-17 17:51 UTCEPSS rescore
  22. 2026-06-17 17:51 UTCEPSS rescore
  23. 2026-06-17 17:51 UTCEPSS rescore
  24. 2026-06-16 17:51 UTCEPSS rescore
  25. 2026-06-16 17:51 UTCEPSS rescore
  26. 2026-06-15 17:46 UTCEPSS rescore
  27. 2026-06-12 23:10 UTCEPSS rescore
  28. 2026-06-11 13:58 UTCEPSS rescore
  29. 2026-06-11 13:58 UTCEPSS rescore
  30. 2026-06-10 22:16 UTCEPSS rescore
  31. 2026-06-10 22:16 UTCEPSS rescore
  32. 2026-06-10 13:20 UTCEPSS rescore
  33. 2026-06-08 14:15 UTCEPSS rescore
  34. 2026-06-08 14:15 UTCEPSS rescore
  35. 2026-06-06 13:46 UTCEPSS rescore
  36. 2026-06-06 13:46 UTCEPSS rescore
  37. 2026-06-05 22:45 UTCEPSS rescore
  38. 2026-06-05 06:09 UTCEPSS rescore
  39. 2026-06-05 06:09 UTCEPSS rescore
  40. 2026-06-04 13:10 UTCEPSS rescore
  41. 2026-06-04 13:10 UTCEPSS rescore
  42. 2026-06-02 20:11 UTCEPSS rescore
  43. 2026-06-02 20:11 UTCEPSS rescore
  44. 2026-06-01 13:50 UTCEPSS rescore
  45. 2026-06-01 13:50 UTCEPSS rescore
  46. 2026-05-31 22:29 UTCEPSS rescore
  47. 2026-05-31 22:29 UTCEPSS rescore
  48. 2026-05-31 00:15 UTCEPSS rescore
  49. 2026-05-31 00:15 UTCEPSS rescore
  50. 2026-05-29 13:42 UTCEPSS rescore
  51. 2026-05-28 13:43 UTCEPSS rescore
  52. 2026-05-28 13:43 UTCEPSS rescore
  53. 2026-05-27 13:39 UTCEPSS rescore
  54. 2026-05-27 13:39 UTCEPSS rescore
  55. 2026-05-26 09:47 UTCEG score recompute
  56. 2026-05-26 09:46 UTCGHSA enrichment
  57. 2026-05-24 17:42 UTCOSV refresh

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2021-39840?
CVE-2021-39840 is a high vulnerability published on September 29, 2021. Acrobat Reader DC versions 2021.005.20060 (and earlier), 2020.004.30006 (and earlier) and 2017.011.30199 (and earlier) are affected by a use-after-free vulnerability when processing AcroForms that could result in arbitrary code execution in the context of the current user. User interaction is…
When was CVE-2021-39840 disclosed?
CVE-2021-39840 was first published in the National Vulnerability Database on September 29, 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-2021-39840 actively exploited?
CVE-2021-39840 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 51% probability of exploitation in the next 30 days, which ranks it in the top 1.2% of all scored CVEs.
What is the CVSS score of CVE-2021-39840?
CVE-2021-39840 has a CVSS v3 base score of 7.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 8.2.
How do I remediate CVE-2021-39840?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-39840, 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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