CVE-2026-12478

MEDIUMPre-NVD 4.84.8—
EchelonGraph scoreHIGH confidence

Score 4.8 from GitHub Security Advisory published 2026-07-14. a secondary CVSS source baseline 4.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
4.8
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 4.8Exploit: NoneExposed: 0

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

The fix for CVE-2026-0716 (commit 6ff7ef0, libsoup 3.6.6) placed the integer overflow guard inside the if (masked) block, leaving unmasked server-to-client frames unprotected. A malicious WebSocket server can send a crafted unmasked frame with a payload length near UINT64_MAX to trigger an OOB read in a libsoup-based client when max_incoming_payload_size is set to 0.

CVSS v3
4.8
EG Score
4.8(high)
EPSS
22.0%
KEV
Not listed

Published

July 14, 2026

Last Modified

July 15, 2026

Advisory Details (4)

Auto-updated Jul 14, 2026
Patch available. Sources: redhat.
generic

websocket: Fix out-of-bounds read when reading unmasked frame (!518) · Merge requests · GNOME / libsoup · GitLab

https://gitlab.gnome.org/GNOME/libsoup/-/merge_requests/518
redhat

2489655 – (CVE-2026-12478) CVE-2026-12478 libsoup: Incomplete fix for CVE-2026-0716: Out-of-bounds read in libsoup WebSocket frame processing (unmasked path)

https://bugzilla.redhat.com/show_bug.cgi?id=2489655
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/cve-2026-0716
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-12478

Vendor Advisories for CVE-2026-12478(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 6× in last 7d / 6× 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. 2026-07-15 16:57 UTCEPSS rescore
  2. 2026-07-15 08:48 UTCEG score recompute
  3. 2026-07-15 08:47 UTCGHSA enrichment
  4. 2026-07-15 02:00 UTCEPSS rescore
  5. 2026-07-14 09:56 UTCEG score recompute
  6. 2026-07-14 09:55 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-12478?
CVE-2026-12478 is a medium vulnerability published on July 14, 2026. The fix for CVE-2026-0716 (commit 6ff7ef0, libsoup 3.6.6) placed the integer overflow guard inside the if (masked) block, leaving unmasked server-to-client frames unprotected. A malicious WebSocket server can send a crafted unmasked frame with a payload length near UINT64MAX to trigger an OOB read…
When was CVE-2026-12478 disclosed?
CVE-2026-12478 was first published in the National Vulnerability Database on July 14, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-12478 actively exploited?
CVE-2026-12478 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 22.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-12478?
CVE-2026-12478 has a CVSS v3 base score of 4.8 (NVD).
How do I remediate CVE-2026-12478?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-12478, 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

Explore the affected products and dependency analysis for CVE-2026-12478

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