A flaw was found in tftp-hpa. When the `in.tftpd` remap engine processes an inverse remap rule that also aborts with a non-empty custom error message, it can pass invalid match offsets to the `genmatchstring()` function. This leads to out-of-bounds read/write operations. A remote, unauthenticated attacker can exploit this vulnerability by sending a specially crafted request, causing the daemon to crash and resulting in a denial of service.

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Fixes

Solution

No solution given by the vendor.


Workaround

To mitigate this issue, avoid enabling filename remapping with the `m/-map-file` option for the `in.tftpd` service unless strictly necessary. If filename remapping is required, ensure that any inverse (`~`) and abort (`a`) rules in the remap file do not include a non-empty custom error message. Changes to the `in.tftpd` configuration may require restarting the service to take effect.

History

Wed, 16 Sep 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Moderate


Tue, 15 Sep 2026 20:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 15 Sep 2026 18:00:00 +0000

Type Values Removed Values Added
Description A flaw was found in tftp-hpa. When the `in.tftpd` remap engine processes an inverse remap rule that also aborts with a non-empty custom error message, it can pass invalid match offsets to the `genmatchstring()` function. This leads to out-of-bounds read/write operations. A remote, unauthenticated attacker can exploit this vulnerability by sending a specially crafted request, causing the daemon to crash and resulting in a denial of service.
Title Tftp: tftp-hpa: denial of service due to out-of-bounds read/write in remap engine
First Time appeared Redhat
Redhat enterprise Linux
Redhat hummingbird
Weaknesses CWE-125
CPEs cpe:/a:redhat:hummingbird:1
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:6
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
Redhat hummingbird
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-09-15T19:43:52.914Z

Reserved: 2026-09-03T14:57:22.051Z

Link: CVE-2026-85234

cve-icon Vulnrichment

Updated: 2026-09-15T19:07:12.808Z

cve-icon NVD

Status : Received

Published: 2026-09-15T18:19:34.927

Modified: 2026-09-15T20:18:58.810

Link: CVE-2026-85234

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-09-15T15:36:00Z

Links: CVE-2026-85234 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-09-16T01:00:14Z

Weaknesses