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Fencer Vulns
medium 4.9

CVE-2006-0744 json

Linux kernel before 2.6.16.5 does not properly handle uncanonical return addresses on Intel EM64T CPUs, which reports an exception in the S…

published 2006-04-18 20 y ago modified 2026-06-16 4 mo ago also EUVD-2006-0750

cvss
4.9
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 41%
public exploits
0
none known

Summary

Linux kernel before 2.6.16.5 does not properly handle uncanonical return addresses on Intel EM64T CPUs, which reports an exception in the SYSRET instead of the next instruction, which causes the kernel exception handler to run on the user stack with the wrong GS.

Patch / fix

  • kernel RHEL 4 2.6.9-34.0.1.EL
  • kernel-smp RHEL 4 2.6.9-34.0.1.EL
  • kernel-hugemem RHEL 4 2.6.9-34.0.1.EL
  • kernel-largesmp RHEL 4 2.6.9-34.0.1.EL
  • kernel RHEL 3 2.4.21-47.EL
  • kernel-smp RHEL 3 2.4.21-47.EL
  • kernel-BOOT RHEL 3 2.4.21-47.EL
  • kernel-source RHEL 3 2.4.21-47.EL

red hat advisories RHSA-2006:0493RHSA-2006:0437

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2006-0744 updated

security flaw

  • Red Hat Desktop version 3 kernel 2.4.21-47.EL, kernel-smp 2.4.21-47.EL, kernel-BOOT 2.4.21-47.EL, kernel-source 2.4.21-47.EL, kernel-hugemem 2.4.21-47.EL, kernel-unsupported 2.4.21-47.EL, +2 more Red Hat Enterprise Linux AS version 3 kernel 2.4.21-47.EL, kernel-smp 2.4.21-47.EL, kernel-BOOT 2.4.21-47.EL, kernel-source 2.4.21-47.EL, kernel-hugemem 2.4.21-47.EL, kernel-unsupported 2.4.21-47.EL, +2 more
    fixed: vendor fix RHSA-2006:0437
  • Red Hat Enterprise Linux AS version 4 kernel 2.6.9-34.0.1.EL, kernel-smp 2.6.9-34.0.1.EL, kernel-hugemem 2.6.9-34.0.1.EL, kernel-largesmp 2.6.9-34.0.1.EL Red Hat Enterprise Linux Desktop version 4 kernel 2.6.9-34.0.1.EL, kernel-smp 2.6.9-34.0.1.EL, kernel-hugemem 2.6.9-34.0.1.EL, kernel-largesmp 2.6.9-34.0.1.EL
    fixed: vendor fix RHSA-2006:0493
  • Red Hat Enterprise Linux ES version 3 kernel 2.4.21-47.EL, kernel-smp 2.4.21-47.EL, kernel-BOOT 2.4.21-47.EL, kernel-source 2.4.21-47.EL, kernel-hugemem 2.4.21-47.EL, kernel-unsupported 2.4.21-47.EL, +2 more
    fixed: vendor fix RHSA-2006:0437
  • Red Hat Enterprise Linux ES version 4 kernel 2.6.9-34.0.1.EL, kernel-smp 2.6.9-34.0.1.EL, kernel-hugemem 2.6.9-34.0.1.EL, kernel-largesmp 2.6.9-34.0.1.EL
    fixed: vendor fix RHSA-2006:0493
  • Red Hat Enterprise Linux WS version 3 kernel 2.4.21-47.EL, kernel-smp 2.4.21-47.EL, kernel-BOOT 2.4.21-47.EL, kernel-source 2.4.21-47.EL, kernel-hugemem 2.4.21-47.EL, kernel-unsupported 2.4.21-47.EL, +2 more
    fixed: vendor fix RHSA-2006:0437
  • Red Hat Enterprise Linux WS version 4 kernel 2.6.9-34.0.1.EL, kernel-smp 2.6.9-34.0.1.EL, kernel-hugemem 2.6.9-34.0.1.EL, kernel-largesmp 2.6.9-34.0.1.EL
    fixed: vendor fix RHSA-2006:0493

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.48% chance of exploitation in the next 30 days, higher than 41% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 2.0 4.9 AV:L/AC:L/Au:N/C:N/I:N/A:C

Classification

Weakness
  • CWE-20 Improper Input Validation
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.