CVE-2026-12478
CVE-2026-12478 is covered by the Red Hat CVE-2026-12478 security bulletin. Not in the CISA KEV catalog. Medium advisory severity. 1 advisory from Red Hat.
Compare the source-linked records below. Ratings and product/version details belong to each advisory; they are not a single CVE-wide score or proof that every listed product is affected. How VulniPulse collects and checks evidence.
CVE-2026-12478 key facts
- CISA KEV
- Not listed (catalog checked )
- Highest advisory severity
- Medium
- Vendor advisories
- 1 from Red Hat
- VulniPulse record
- Published
Is CVE-2026-12478 exploited?
No exploitation is reported in the sources VulniPulse tracks: CVE-2026-12478 is not in the CISA KEV catalog (checked ) and no tracked advisory for it reports exploitation. That is not proof the vulnerability cannot be exploited.
How do I fix CVE-2026-12478?
This CVE is tracked through a multi-CVE bulletin, so its fixed releases may differ from the bulletin-wide values below. Check the vendor source.
Get an email when Red Hat publishes the next one.
See Red Hat's last 90 days of advisories first. Then choose one product with live alerts free for life, or a free month of real-time alerts on everything with the severity, the fixed version and the vendor's link (card needed, then US$15/month; we email you before the first charge).
Vendor advisory comparison
Red Hat
1 advisory- Advisory severityMedium4.8
Medium [CVE-2026-0716 +1] incomplete fix for CVE-2026-0716: out-of-bounds read in libsoup websocket frame processing (unmasked path)
CVE-2026-12478Source published Source updated
This bulletin covers 2 CVEs. The products, versions, score and guidance below describe the bulletin; check its source for applicability to this specific CVE.
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. This vulnerability is rated Moderate for Red Hat because it requires a non-default configuration where max_incoming_payload_size is explicitly set to 0 or unset in libsoup's WebSocket frame processing. In typical Red Hat deployments, this configuration is not enabled by default, limiting the exposure to memory disclosure or application instability. Red Hat severity: Moderate — CVSS 4.8…
- Affected products in this advisory
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
1 more entries in the full advisory.
- Source-reported affected versions
- Affected-version details not available in this record.
- Source-reported fixed versions
- No fixed-version detail extracted. This does not mean no fix exists.
- Mitigation guidance
- To mitigate this issue, applications utilizing libsoup's WebSocket support should ensure that the `max_incoming_payload_size` is explicitly set to a non-zero value. This prevents the library from processing WebSocket frames with an unset or zero maximum payload size, which can lead to out-of-bounds reads. Consult application-specific documentation for configuring libsoup parameters.
More Red Hat advisories
- CVE-2026-111497Oct 22, 2026Out-of-Bounds Write in Google Brotli Decoder
- CVE-2026-109619Oct 21, 2026fatal error handling retains stale request state leading to use-after-free
- CVE-2026-109618Oct 21, 2026OOM bailout during request parsing leads to memory corruption and RCE
- CVE-2026-119977Oct 31, 2026Arbitrary code execution via predictable upgrade staging paths
- CVE-2026-97229Oct 13, 2026integer overflow issue in CI/CD regular expression compiler
- CVE-2026-64849Aug 17, 2026Unauthenticated full-read SSRF in webhook delivery: _validate_webhook_url bypassed
Follow CVE-2026-12478 in the free weekly digest
Every Monday: whether it was added to CISA KEV, reported exploited, got a fix or changed severity, plus the week's critical and high advisories.
Browse the latest tracked CVEs or the CVEs listed in CISA KEV.
iPhone and Android apps · New on the App Store
Monitor future Red Hat CVEs from your phone.
Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 34 official vendor sources and 160+ reviewed platform categories.
