PatchTheCVECVE-2026-4747: Each RPCSEC_GSS data packet is validated by a routine which checks a signature in the packet
CVE-2026-4747 is a high-severity flaw (CVSS 8.8) affecting freebsd. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Each RPCSEC_GSS data packet is validated by a routine which checks a signature in the packet. This routine copies a portion of the packet into a stack buffer, but fails to ensure that the buffer is sufficiently large, and a malicious client can trigger a stack overflow. Notably, this does not require the client to authenticate itself first. As kgssapi.ko's RPCSEC_GSS implementation is vulnerable, remote code execution in the kernel is possible
Why this priority
- High severity
- Public exploit reference
A fixed release or distro patch exists.
Risk facts
| CVSS score | 8.8 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | 3.4% (top 11%) |
| CISA exploited list | No |
| Weakness | CWE-121 |
| Published | 2026-03-26 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
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.
- GitHub PoC: kaleth4/CVE-2026-4747- (1 stars)
- GitHub PoC: kaleth4/CVE-2026-4747 (0 stars)
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-2026-4747?
freebsd: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2026-4747 being exploited?
CVE-2026-4747 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-2026-4747 affect?
CVE-2026-4747 affects freebsd. Severity is high (CVSS 8.8). Each RPCSEC_GSS data packet is validated by a routine which checks a signature in the packet. This routine copies a portion of the packet into a stack buffer, but fails to ensure that the buffer is sufficiently large, and a malicious clien
How urgent is CVE-2026-4747?
Priority 58/100. High severity; Public exploit reference
Related CVEs
- CVE-2026-58082 CRITICAL 9.8 MITIGATE The ISO-2022 encoding module used a stack buffer sized to MB_LEN_MAX (6 bytes) for intermediate character outp
- CVE-2026-58081 CRITICAL 9.8 MITIGATE Several encoding modules, including HZ, UTF-7, VIQR, and ZW, did not properly check the size of the caller-sup
- CVE-2026-58085 HIGH 7.5 MITIGATE After dispatching a decrypt operation to OCF and receiving the result, the wg(4) driver failed to check whethe
- CVE-2026-58086 HIGH 8.1 MITIGATE As an inadvertent side effect of an unrelated code change, PRIV_KTRACE was always denied to a jailed root user
- CVE-2026-58083 HIGH 8.4 MITIGATE While the kernel was copying knotes during fork, a knote with a timer-based filter could fire and be enqueued