Security readout for executives and security teams
Plain-English summary
A flaw in RDK-B WebUI lets an unauthenticated remote attacker send a malicious web request that can corrupt device memory. The documented result includes service disruption and potentially complete code execution, creating serious availability and device-compromise risk where the WebUI is reachable.
Executive priority
Treat as an urgent exposure-assessment and containment issue because compromise requires neither credentials nor user action. Immediately determine whether affected WebUI instances are reachable from untrusted networks. The sources do not identify a fixed version, so coordinate remediation with RDK or the relevant device vendor.
Technical view
The multipart/form-data parser in jst_post.c contains a heap-based buffer overflow in RDK-B WebUI rdkb-2025q4-kirkstone.04.10.26. Exploitation requires network access but no credentials or user interaction. The CVSS 3.1 score is 9.8, with potential confidentiality, integrity, and availability impact.
Likely exposure
Systems using the identified RDK-B WebUI branch or build are the primary concern. Risk is greatest when the WebUI accepts connections from untrusted networks. The supplied evidence does not establish which commercial devices incorporate this code or whether their interfaces are Internet-accessible.
Exploitation context
The issue is remotely reachable, low complexity, unauthenticated, and requires no user interaction. Crafted multipart/form-data can cause memory corruption, denial of service, and potentially arbitrary code execution. The source bundle reports no CISA KEV listing and provides no evidence of active exploitation.
Researcher notes
CWE-119 describes the memory-safety class, while the specific defect is a heap-based overflow in jst_post.c multipart parsing. Arbitrary code execution is described as potential, not demonstrated in the supplied evidence. No affected commercial-device mapping, fixed release, public exploit, or active-exploitation evidence is provided.
Mitigation direction
- Identify devices and firmware containing the affected RDK-B WebUI code.
- Restrict WebUI access to trusted management networks and authorized administrators.
- Prevent public or untrusted network access to the WebUI where operationally feasible.
- Check RDK and device-vendor guidance for a corrected release or approved mitigation.
- Prioritize vendor updates once their applicability and authenticity are confirmed.
Validation and detection
- Inventory RDK-B devices, firmware versions, and embedded WebUI component versions.
- Confirm whether deployments contain rdkb-2025q4-kirkstone.04.10.26 or the identified branch.
- Map every network path capable of reaching each affected WebUI.
- Verify firewalls and access controls block untrusted WebUI connections.
- Review affected services for unexplained crashes, restarts, or memory-corruption indicators.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-119: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-19508 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://whitehats.pwr.edu.pl//blog/2026-08-19-multiple-vulnerabilities-in-rdkb/CVE reference, certcc
- https://developer.rdkcentral.com/documentation/documentation/rdk_broadband_documentation/components/webui/CVE reference, certcc
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Restriction of Operations within the Bounds of a Memory Buffer
Improper Restriction of Operations within the Bounds of a Memory Buffer represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.