CVE-2016-8638

CRITICALNVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 7.1%, top 8% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
9.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 2%CVSS: 9.1Exploit: NoneExposed: 0

A fix is available — apply it.

A vulnerability in ipsilon 2.0 before 2.0.2, 1.2 before 1.2.1, 1.1 before 1.1.2, and 1.0 before 1.0.3 was found that allows attacker to log out active sessions of other users. This issue is related to how it tracks sessions, and allows an unauthenticated attacker to view and terminate active sessions from other users. It is also called a "SAML2 multi-session vulnerability."

CVSS v3
9.1
EG Score
9.1(medium)
EPSS
79.6%
KEV
Not listed

Published

July 12, 2017

Last Modified

May 13, 2026

Advisory Details (4)

Auto-updated May 19, 2026
Patch available. Sources: redhat.
redhat Patch Available

1392829 – (CVE-2016-8638) CVE-2016-8638 ipsilon: DoS via logging out all open SAML2 sessions

Affected: Red Hat Enterprise Linux 7

https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2016-8638
generic
http://www.securityfocus.com/bid/94439
generic
http://rhn.redhat.com/errata/RHSA-2016-2809.html
generic

Commit - ipsilon - 511fa8b7001c2f9a42301aa1d4b85aaf170a461c - Pagure.io

https://pagure.io/ipsilon/c/511fa8b7001c2f9a42301aa1d4b85aaf170a461c

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatipsilon-0:1.0.0-13.el7_32016-11-21redhat

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

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
ipsilon—1.0.3—

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

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

Frequently asked(5)

What is CVE-2016-8638?
CVE-2016-8638 is a critical vulnerability published on July 12, 2017. A vulnerability in ipsilon 2.0 before 2.0.2, 1.2 before 1.2.1, 1.1 before 1.1.2, and 1.0 before 1.0.3 was found that allows attacker to log out active sessions of other users. This issue is related to how it tracks sessions, and allows an unauthenticated attacker to view and terminate active…
When was CVE-2016-8638 disclosed?
CVE-2016-8638 was first published in the National Vulnerability Database on July 12, 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-2016-8638 actively exploited?
CVE-2016-8638 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 79.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2016-8638?
CVE-2016-8638 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2016-8638?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2016-8638, 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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