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TI-2026-33064 Aliases CVE-2026-45257

Arbitrary file overwrite via the KTLS receive path

Priority HIGH 69CWE-123Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA.

Summary

The KTLS receive path decrypted each record in place, assuming that the mbufs holding received data were anonymous and safe to modify. This assumption does not hold for data placed on a socket by sendfile(2), which can reference file-backed memory directly through non-anonymous M_EXTPG pages or EXT_SFBUF mbufs. When the sender transmits such data over a loopback connection without enabling KTLS on the transmit side, the file-backed mbufs reach the receiver's decryption path unchanged. Decrypting a record in place then overwrites the backing file's page cache instead of a private copy of the data. An unprivileged local user who can read a file can overwrite its contents with data of their choosing by sending the file over a loopback connection on which they have enabled KTLS receive. The write modifies the page cache directly, so it bypasses file flags such as schg and is written back to disk. By overwriting a setuid binary or other trusted file, a local user can escalate privileges, potentially gaining full control of the affected system.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00176 7th percentileScored 2026-11-07
Fix Fixed FreeBSD (FreeBSD): p10, p6, p15

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
FreeBSDFreeBSD15.0-RELEASE to before p10; 14.4-RELEASE to before p6; 14.3-RELEASE to before p15p10, p6, p15Patch availableCNA
  • FreeBSD VendorFreeBSD Affected 15.0-RELEASE to before p10; 14.4-RELEASE to before p6; 14.3-RELEASE to before p15 Fixed in p10, p6, p15 Patch available CNA

CPE configurations NVD · 33

CPEVersionsRoleVendor
cpe:2.3:o:freebsd:freebsd:14.3:-:*:*:*:*:*:*14.3VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p1:*:*:*:*:*:*14.3 p1VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p10:*:*:*:*:*:*14.3 p10VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p11:*:*:*:*:*:*14.3 p11VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p12:*:*:*:*:*:*14.3 p12VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p13:*:*:*:*:*:*14.3 p13VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p14:*:*:*:*:*:*14.3 p14VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p2:*:*:*:*:*:*14.3 p2VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p3:*:*:*:*:*:*14.3 p3VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p4:*:*:*:*:*:*14.3 p4VulnerableFreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:-:*:*:*:*:*:* Versions 14.3 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p1:*:*:*:*:*:* Versions 14.3 p1 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p10:*:*:*:*:*:* Versions 14.3 p10 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p11:*:*:*:*:*:* Versions 14.3 p11 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p12:*:*:*:*:*:* Versions 14.3 p12 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p13:*:*:*:*:*:* Versions 14.3 p13 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p14:*:*:*:*:*:* Versions 14.3 p14 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p2:*:*:*:*:*:* Versions 14.3 p2 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p3:*:*:*:*:*:* Versions 14.3 p3 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p4:*:*:*:*:*:* Versions 14.3 p4 Vulnerable ·FreeBSD
Show 23 more CPE
CPEVersionsRoleVendor
cpe:2.3:o:freebsd:freebsd:14.3:p5:*:*:*:*:*:*14.3 p5VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p6:*:*:*:*:*:*14.3 p6VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p7:*:*:*:*:*:*14.3 p7VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p8:*:*:*:*:*:*14.3 p8VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.3:p9:*:*:*:*:*:*14.3 p9VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.4:-:*:*:*:*:*:*14.4VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.4:p1:*:*:*:*:*:*14.4 p1VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.4:p2:*:*:*:*:*:*14.4 p2VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.4:p3:*:*:*:*:*:*14.4 p3VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.4:p4:*:*:*:*:*:*14.4 p4VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.4:p5:*:*:*:*:*:*14.4 p5VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:14.4:rc1:*:*:*:*:*:*14.4 rc1VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:-:*:*:*:*:*:*15.0VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p1:*:*:*:*:*:*15.0 p1VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p2:*:*:*:*:*:*15.0 p2VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p3:*:*:*:*:*:*15.0 p3VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p4:*:*:*:*:*:*15.0 p4VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p5:*:*:*:*:*:*15.0 p5VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p6:*:*:*:*:*:*15.0 p6VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p7:*:*:*:*:*:*15.0 p7VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p8:*:*:*:*:*:*15.0 p8VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.0:p9:*:*:*:*:*:*15.0 p9VulnerableFreeBSD
cpe:2.3:o:freebsd:freebsd:15.1:rc2:*:*:*:*:*:*15.1 rc2VulnerableFreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p5:*:*:*:*:*:* Versions 14.3 p5 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p6:*:*:*:*:*:* Versions 14.3 p6 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p7:*:*:*:*:*:* Versions 14.3 p7 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p8:*:*:*:*:*:* Versions 14.3 p8 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.3:p9:*:*:*:*:*:* Versions 14.3 p9 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.4:-:*:*:*:*:*:* Versions 14.4 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.4:p1:*:*:*:*:*:* Versions 14.4 p1 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.4:p2:*:*:*:*:*:* Versions 14.4 p2 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.4:p3:*:*:*:*:*:* Versions 14.4 p3 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.4:p4:*:*:*:*:*:* Versions 14.4 p4 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.4:p5:*:*:*:*:*:* Versions 14.4 p5 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:14.4:rc1:*:*:*:*:*:* Versions 14.4 rc1 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:-:*:*:*:*:*:* Versions 15.0 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p1:*:*:*:*:*:* Versions 15.0 p1 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p2:*:*:*:*:*:* Versions 15.0 p2 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p3:*:*:*:*:*:* Versions 15.0 p3 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p4:*:*:*:*:*:* Versions 15.0 p4 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p5:*:*:*:*:*:* Versions 15.0 p5 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p6:*:*:*:*:*:* Versions 15.0 p6 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p7:*:*:*:*:*:* Versions 15.0 p7 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p8:*:*:*:*:*:* Versions 15.0 p8 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.0:p9:*:*:*:*:*:* Versions 15.0 p9 Vulnerable ·FreeBSD
  • cpe:2.3:o:freebsd:freebsd:15.1:rc2:*:*:*:*:*:* Versions 15.1 rc2 Vulnerable ·FreeBSD

Remediation

  • Fix · CNA FreeBSD (FreeBSD) Fixed in p10, p6, p15

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    FreeBSD p10, p15, p6

    2 records Highest priority Priority HIGH 1 HIGH, 1 LOW

    Other records, highest priority first

    • TI-2026-33063 Missing permission check in thr_kill2(2)Priority LOW 24
    Show all 2 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-45257

References

Advisory 4

  • TI-2011-04182 Buffer overflow in libtelnet/encrypt.c in telnetd in FreeBSD 7.3 through 9.0, MIT… CVSS 2.0HIGH 10.0
  • TI-2007-03684 Integer overflow in print-bgp.c in the BGP dissector in tcpdump 3.9.6 and earlier allows… CVSS 3.1CRITICAL 9.8
  • TI-2002-00376 Integer overflow in xdr_array function in RPC servers for operating systems that use… CVSS 3.1CRITICAL 9.8
  • TI-2024-05929 Openssh: regresshion - race condition in ssh allows rce/dos CVSS 3.1HIGH 8.1
  • TI-2003-00437 Off-by-one error in the fb_realpath() function, as derived from the realpath function in… CVSS 3.1CRITICAL 9.8
  • TI-2003-00642 The prescan function in Sendmail 8.12.9 allows remote attackers to execute arbitrary code… CVSS 2.0HIGH 10.0
See all 576 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences