CVE-2026-74998

HIGHPre-NVD 7.27.2—
EchelonGraph scoreHIGH confidence

Score 7.2 from GitHub Security Advisory (severity: HIGH) published 2026-08-17. a secondary CVSS source baseline 7.2; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
7.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.2Exploit: None knownExposed: 0

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

In Roundcube Webmail before 1.6.18 and 1.7.x before 1.7.3, responses from the CSS (Cascading Style Sheets) proxy were not validated, which may result in information disclosure or XSS (cross-site scripting) via MIME sniffing.

CVSS v3
7.2
EG Score
7.2(high)
EG Risk
37(Track)
EG Risk 37/100SSVC: 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
Severity72% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
19%
KEV
Not listed

Published

August 17, 2026

Last Modified

August 17, 2026

Advisory Details (5)

Auto-updated Aug 17, 2026
Patch available. Sources: github_commit, github_release.
github_commit

commit a2334990c02f (roundcube/roundcubemail)

Fix landed in roundcube/roundcubemail commit a2334990c02f — awaiting tagged release

https://github.com/roundcube/roundcubemail/commit/a2334990c02f7cb77b1a8d6fa97fcd9e1b5cd1fb
github_release Patch Available

Roundcube Webmail 1.7.3

Patch available: roundcube/roundcubemail 1.7.3

https://github.com/roundcube/roundcubemail/releases/tag/1.7.3
github_commit

commit 62d33c8a0dc3 (roundcube/roundcubemail)

Fix landed in roundcube/roundcubemail commit 62d33c8a0dc3 — awaiting tagged release

https://github.com/roundcube/roundcubemail/commit/62d33c8a0dc3fd0dd03984220dc9709e8e0de43b
github_release Patch Available

Roundcube Webmail 1.6.18

Patch available: roundcube/roundcubemail 1.6.18

https://github.com/roundcube/roundcubemail/releases/tag/1.6.18
generic

Security updates 1.6.18 and 1.7.3 released

https://roundcube.net/news/2026/08/09/security-updates-1.6.18-and-1.7.3

Vendor Advisories for CVE-2026-74998(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 17× in last 7d / 17× 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. 2026-08-20 22:56 UTCEPSS rescore
  2. 2026-08-20 21:15 UTCGHSA enrichment
  3. 2026-08-20 08:27 UTCGHSA enrichment
  4. 2026-08-19 19:39 UTCEG score recompute
  5. 2026-08-19 19:39 UTCGHSA enrichment
  6. 2026-08-19 17:04 UTCEPSS rescore
  7. 2026-08-19 06:50 UTCGHSA enrichment
  8. 2026-08-18 18:03 UTCEG score recompute
  9. 2026-08-18 18:02 UTCGHSA enrichment
  10. 2026-08-18 13:49 UTCEPSS rescore
  11. 2026-08-18 13:49 UTCEPSS rescore
  12. 2026-08-18 05:12 UTCGHSA enrichment
  13. 2026-08-17 16:23 UTCEG score recompute
  14. 2026-08-17 16:23 UTCGHSA enrichment
  15. 2026-08-17 13:30 UTCEG score recompute
  16. 2026-08-17 12:56 UTCEG score recompute
  17. 2026-08-17 12:56 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-74998?
CVE-2026-74998 is a high vulnerability published on August 17, 2026. In Roundcube Webmail before 1.6.18 and 1.7.x before 1.7.3, responses from the CSS (Cascading Style Sheets) proxy were not validated, which may result in information disclosure or XSS (cross-site scripting) via MIME sniffing.
When was CVE-2026-74998 disclosed?
CVE-2026-74998 was first published in the National Vulnerability Database on August 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-74998 actively exploited?
CVE-2026-74998 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 80.9% of all scored CVEs.
What is the CVSS score of CVE-2026-74998?
CVE-2026-74998 has a CVSS v3 base score of 7.2 (NVD).
How do I remediate CVE-2026-74998?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-74998, 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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