CVE-2015-3991

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2022-05-14. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 5%CVSS: 9.8Exploit: NoneExposed: 0

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

strongSwan 5.2.2 and 5.3.0 allows remote attackers to cause a denial of service (daemon crash) or execute arbitrary code.

CVSS v3
9.8
EG Score
9.8(medium)
EPSS
90.4%
KEV
Not listed

Published

September 7, 2017

Last Modified

May 13, 2026

Advisory Details (3)

Auto-updated Jun 21, 2026
Patch available. Sources: redhat.
generic

strongSwan - strongSwan Vulnerability (CVE-2015-3991)

https://www.strongswan.org/blog/2015/06/01/strongswan-vulnerability-%28cve-2015-3991%29.html
redhat Patch Available

1222815 – (CVE-2015-3991) CVE-2015-3991 strongswan: incorrect payload processing for different IKE versions

https://bugzilla.redhat.com/show_bug.cgi?id=1222815
generic
http://www.securityfocus.com/bid/76861

Data Freshness Timeline

(refreshed 10× in last 7d / 34× 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. 2026-07-07 13:42 UTCEPSS rescore
  2. 2026-07-06 16:24 UTCEPSS rescore
  3. 2026-07-06 02:20 UTCEPSS rescore
  4. 2026-07-05 02:26 UTCEPSS rescore
  5. 2026-07-04 06:27 UTCEPSS rescore
  6. 2026-07-02 15:21 UTCEPSS rescore
  7. 2026-07-01 15:02 UTCEPSS rescore
  8. 2026-07-01 15:02 UTCEPSS rescore
  9. 2026-06-30 23:19 UTCEPSS rescore
  10. 2026-06-30 23:19 UTCEPSS rescore
  11. 2026-06-28 04:53 UTCEPSS rescore
  12. 2026-06-27 03:05 UTCEPSS rescore
  13. 2026-06-25 13:47 UTCEPSS rescore
  14. 2026-06-25 13:47 UTCEPSS rescore
  15. 2026-06-24 14:02 UTCEPSS rescore
  16. 2026-06-24 14:02 UTCEPSS rescore
  17. 2026-06-23 21:30 UTCEPSS rescore
  18. 2026-06-21 14:54 UTCEPSS rescore
  19. 2026-06-21 01:57 UTCEPSS rescore
  20. 2026-06-21 01:57 UTCEPSS rescore
  21. 2026-06-20 00:06 UTCOSV refresh
  22. 2026-06-19 19:23 UTCEPSS rescore
  23. 2026-06-19 19:23 UTCEPSS rescore
  24. 2026-06-18 17:50 UTCEPSS rescore
  25. 2026-06-18 17:49 UTCEPSS rescore
Show 61 more
  1. 2026-06-17 17:49 UTCEPSS rescore
  2. 2026-06-16 17:50 UTCEPSS rescore
  3. 2026-06-16 17:49 UTCEPSS rescore
  4. 2026-06-15 17:45 UTCEPSS rescore
  5. 2026-06-14 23:14 UTCEPSS rescore
  6. 2026-06-13 22:57 UTCEPSS rescore
  7. 2026-06-12 23:09 UTCEPSS rescore
  8. 2026-06-11 13:57 UTCEPSS rescore
  9. 2026-06-10 22:15 UTCEPSS rescore
  10. 2026-06-07 15:22 UTCEPSS rescore
  11. 2026-06-06 13:45 UTCEPSS rescore
  12. 2026-06-05 22:44 UTCEPSS rescore
  13. 2026-06-05 06:08 UTCEPSS rescore
  14. 2026-06-05 06:08 UTCEPSS rescore
  15. 2026-06-04 13:10 UTCEPSS rescore
  16. 2026-06-04 13:09 UTCEPSS rescore
  17. 2026-06-02 20:10 UTCEPSS rescore
  18. 2026-06-02 20:10 UTCEPSS rescore
  19. 2026-06-01 13:49 UTCEPSS rescore
  20. 2026-06-01 13:49 UTCEPSS rescore
  21. 2026-05-31 22:28 UTCEPSS rescore
  22. 2026-05-31 22:28 UTCEPSS rescore
  23. 2026-05-31 22:28 UTCEPSS rescore
  24. 2026-05-31 02:25 UTCOSV refresh
  25. 2026-05-31 00:14 UTCEPSS rescore
  26. 2026-05-29 13:41 UTCEPSS rescore
  27. 2026-05-28 13:42 UTCEPSS rescore
  28. 2026-05-28 13:42 UTCEPSS rescore
  29. 2026-05-27 13:38 UTCEPSS rescore
  30. 2026-05-27 13:38 UTCEPSS rescore
  31. 2026-05-26 07:16 UTCEPSS rescore
  32. 2026-05-26 07:16 UTCEPSS rescore
  33. 2026-05-24 16:43 UTCEPSS rescore
  34. 2026-05-23 15:10 UTCEPSS rescore
  35. 2026-05-21 22:40 UTCEPSS rescore
  36. 2026-05-20 22:37 UTCEPSS rescore
  37. 2026-05-20 22:37 UTCEPSS rescore
  38. 2026-05-20 11:21 UTCEPSS rescore
  39. 2026-05-20 11:21 UTCEPSS rescore
  40. 2026-05-20 11:21 UTCEPSS rescore
  41. 2026-05-20 10:31 UTCEG score recompute
  42. 2026-05-20 10:31 UTCGHSA enrichment
  43. 2026-05-20 06:39 UTCEG score recompute
  44. 2026-05-20 06:39 UTCGHSA enrichment
  45. 2026-05-20 02:47 UTCEG score recompute
  46. 2026-05-20 02:47 UTCGHSA enrichment
  47. 2026-05-19 22:55 UTCEG score recompute
  48. 2026-05-19 22:55 UTCGHSA enrichment
  49. 2026-05-19 19:03 UTCEG score recompute
  50. 2026-05-19 19:03 UTCGHSA enrichment
  51. 2026-05-19 15:11 UTCEG score recompute
  52. 2026-05-19 15:11 UTCGHSA enrichment
  53. 2026-05-19 11:19 UTCEG score recompute
  54. 2026-05-19 11:19 UTCGHSA enrichment
  55. 2026-05-19 07:19 UTCEG score recompute
  56. 2026-05-19 07:19 UTCGHSA enrichment
  57. 2026-05-19 03:26 UTCEG score recompute
  58. 2026-05-19 03:26 UTCGHSA enrichment
  59. 2026-05-18 23:33 UTCEG score recompute
  60. 2026-05-18 21:30 UTCEPSS rescore
  61. 2026-05-18 21:30 UTCEPSS rescore

Frequently asked(5)

What is CVE-2015-3991?
CVE-2015-3991 is a critical vulnerability published on September 7, 2017. strongSwan 5.2.2 and 5.3.0 allows remote attackers to cause a denial of service (daemon crash) or execute arbitrary code.
When was CVE-2015-3991 disclosed?
CVE-2015-3991 was first published in the National Vulnerability Database on September 7, 2017, with the most recent update on May 13, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2015-3991 actively exploited?
CVE-2015-3991 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 90.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2015-3991?
CVE-2015-3991 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2015-3991?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2015-3991, 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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