CVE-2026-64857

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 81% 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, secondary
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 0

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

tirreno, a security framework, has a session fixation issue in versions prior to 0.10.0. During authentication, tirreno validates the user's credentials and establishes the authenticated session, but it does not call session_regenerate_id() afterward. As a result, the session identifier is not rotated on login, it stays the same before and after authentication. An attacker able to fix a known session identifier in a victim's browser (for example through a network man-in-the-middle position, or a separate cross-site scripting or subdomain cookie-injection issue) could then gain access to the victim's authenticated session. The issue is fixed in v0.10.0. The session identifier is now regenerated on successful authentication, and the previous session is destroyed. There is no configuration-level workaround.

CVSS v3
5.3
EG Score
5.3(medium)
EG Risk
24(Track)
EG Risk 24/100SSVC: 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
Severity53% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
19%
KEV
Not listed

Published

September 9, 2026

Last Modified

September 9, 2026

Advisory Details (2)

Auto-updated Sep 9, 2026
Patch available. Sources: github, github_release.
github_release Patch Available

v0.10.0

Patch available: tirrenotechnologies/tirreno v0.10.0

https://github.com/tirrenotechnologies/tirreno/releases/tag/v0.10.0
github Patch Available

CWE-384: Session Fixation in Login Authentication · Advisory · tirrenotechnologies/tirreno · GitHub

Affected: v0.10.0. The session identifier is now regenerated on successful

https://github.com/tirrenotechnologies/tirreno/security/advisories/GHSA-gwcm-4p9m-9mvr

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 16× 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. 2026-09-19 06:31 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-18 05:29 UTCEG score recompute
  4. 2026-09-17 04:26 UTCEG score recompute
  5. 2026-09-16 14:08 UTCEPSS rescore
  6. 2026-09-16 05:15 UTCEPSS rescore
  7. 2026-09-16 03:23 UTCEG score recompute
  8. 2026-09-14 01:16 UTCEG score recompute
  9. 2026-09-13 00:14 UTCEG score recompute
  10. 2026-09-11 23:12 UTCEG score recompute
  11. 2026-09-11 14:53 UTCEPSS rescore
  12. 2026-09-11 09:37 UTCEPSS rescore
  13. 2026-09-09 15:28 UTCEG score recompute
  14. 2026-09-09 14:20 UTCEG score recompute
  15. 2026-09-09 13:45 UTCEG score recompute
  16. 2026-09-09 13:44 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-64857?
CVE-2026-64857 is a medium vulnerability published on September 9, 2026. tirreno, a security framework, has a session fixation issue in versions prior to 0.10.0. During authentication, tirreno validates the user's credentials and establishes the authenticated session, but it does not call sessionregenerateid() afterward. As a result, the session identifier is not…
When was CVE-2026-64857 disclosed?
CVE-2026-64857 was first published in the National Vulnerability Database on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-64857 actively exploited?
CVE-2026-64857 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 80.7% of all scored CVEs.
What is the CVSS score of CVE-2026-64857?
CVE-2026-64857 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-64857?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-64857, 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.

Dependency Blast Radius

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