PatchTheCVECVE-2026-19508: Heap-based buffer overflow in the multipart form-data parser in `jst_post.c` in RDK-B WebUI `rdkb-2025q4-kirks
CVE-2026-19508 is a critical-severity flaw (CVSS 9.8) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Heap-based buffer overflow in the multipart form-data parser in `jst_post.c` in RDK-B WebUI `rdkb-2025q4-kirkstone.04.10.26` allows a remote unauthenticated attacker to cause memory corruption and denial of service, and potentially execute arbitrary code, via a crafted multipart/form-data request.
Why this priority
- Critical severity
- CISA SSVC: automatable with total technical impact
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 9.8 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 1.0% (top 38%) |
| CISA exploited list | No |
| Weakness | CWE-119 |
| Published | 2026-08-19 |
| Last modified | 2026-09-03 |
Last updated 2026-09-03 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Exact fixes by distribution
Public exploits and detection
Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-19508?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-19508 being exploited?
CVE-2026-19508 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-19508 affect?
CVE-2026-19508 affects affected software. Severity is critical (CVSS 9.8). Heap-based buffer overflow in the multipart form-data parser in `jst_post.c` in RDK-B WebUI `rdkb-2025q4-kirkstone.04.10.26` allows a remote unauthenticated attacker to cause memory corruption and denial of service, and potentially execute
How urgent is CVE-2026-19508?
Priority 58/100. Critical severity; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action