CVE-2026-13163

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 75% 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
Trending — 3 sources updated this week
5.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.3Exploit: NoneExposed: 0

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

Open redirect vulnerability (CWE-601) in the _safe_redirect function of the click-tracking endpoint (/c//) in Mailerup <1.0.0 on all platforms allows remote unauthenticated attackers to redirect victims to arbitrary external sites and conduct phishing attacks via a crafted u query parameter, because the URL scheme is validated (blocking javascript: and data:) but the destination host is not restricted to an allowlist, and a signing.BadSignature exception is silently caught so a valid signed token is not required.

CVSS v3
5.3
EG Score
5.3(medium)
EPSS
24.8%
KEV
Not listed

Published

June 24, 2026

Last Modified

June 25, 2026

Advisory Details (1)

Auto-updated Jun 25, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit.
github_commit

commit 99eb6d458613 (Maalfer/mailerup)

Fix landed in Maalfer/mailerup commit 99eb6d458613 — awaiting tagged release

https://github.com/Maalfer/mailerup/commit/99eb6d4586134bf3f4422093fbf47d6794ef0ee5

Vendor Advisories for CVE-2026-13163(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 22× in last 7d / 41× 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. 2026-07-06 16:27 UTCEPSS rescore
  2. 2026-07-06 14:33 UTCEG score recompute
  3. 2026-07-06 14:33 UTCGHSA enrichment
  4. 2026-07-06 02:23 UTCEPSS rescore
  5. 2026-07-05 15:13 UTCEG score recompute
  6. 2026-07-05 15:13 UTCGHSA enrichment
  7. 2026-07-05 02:30 UTCEPSS rescore
  8. 2026-07-05 02:30 UTCEPSS rescore
  9. 2026-07-04 15:53 UTCEG score recompute
  10. 2026-07-04 15:53 UTCGHSA enrichment
  11. 2026-07-04 06:31 UTCEPSS rescore
  12. 2026-07-03 16:33 UTCEG score recompute
  13. 2026-07-03 16:33 UTCGHSA enrichment
  14. 2026-07-02 17:12 UTCEG score recompute
  15. 2026-07-02 17:12 UTCGHSA enrichment
  16. 2026-07-01 17:51 UTCEG score recompute
  17. 2026-07-01 17:51 UTCGHSA enrichment
  18. 2026-07-01 15:06 UTCEPSS rescore
  19. 2026-07-01 15:06 UTCEPSS rescore
  20. 2026-06-30 23:22 UTCEPSS rescore
  21. 2026-06-30 18:31 UTCEG score recompute
  22. 2026-06-30 18:31 UTCGHSA enrichment
  23. 2026-06-29 19:11 UTCEG score recompute
  24. 2026-06-29 19:11 UTCGHSA enrichment
  25. 2026-06-29 14:06 UTCEPSS rescore
Show 16 more
  1. 2026-06-28 19:51 UTCEG score recompute
  2. 2026-06-28 19:51 UTCGHSA enrichment
  3. 2026-06-28 14:07 UTCEPSS rescore
  4. 2026-06-28 04:56 UTCEPSS rescore
  5. 2026-06-28 04:56 UTCEPSS rescore
  6. 2026-06-27 20:31 UTCEG score recompute
  7. 2026-06-27 20:31 UTCGHSA enrichment
  8. 2026-06-27 03:08 UTCEPSS rescore
  9. 2026-06-26 21:11 UTCEG score recompute
  10. 2026-06-26 21:10 UTCGHSA enrichment
  11. 2026-06-25 21:51 UTCEG score recompute▲ 5.30
  12. 2026-06-25 21:51 UTCGHSA enrichment
  13. 2026-06-25 21:50 UTCNVD updateCVSS v3 → 5.3 · CVSS v4 → 5.3
  14. 2026-06-25 13:49 UTCEPSS rescore
  15. 2026-06-24 16:04 UTCEG score recompute
  16. 2026-06-24 16:04 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-13163?
CVE-2026-13163 is a medium vulnerability published on June 24, 2026. Open redirect vulnerability (CWE-601) in the saferedirect function of the click-tracking endpoint (/c/<token>/) in Mailerup <1.0.0 on all platforms allows remote unauthenticated attackers to redirect victims to arbitrary external sites and conduct phishing attacks via a crafted u query parameter,…
When was CVE-2026-13163 disclosed?
CVE-2026-13163 was first published in the National Vulnerability Database on June 24, 2026, with the most recent update on June 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-13163 actively exploited?
CVE-2026-13163 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 24.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-13163?
CVE-2026-13163 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-13163?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-13163, 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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