CVE-2026-87080

CRITICAL9.1

Published 2026-09-22 · Updated 2026-09-22 · Source 9b29abf9-4ab0-4765-b253-1875cd9b441e

Description

Net::IDN::Punycode::PP versions before 2.590 for Perl decode a truncated label to a name containing a character it never encoded in decode_punycode. The pure-Perl decoder reads one digit at a time with four-argument substr and tests the result with defined to detect the end of the input. substr on an exhausted string returns the empty string rather than undef, so decoding continues past the end. The empty string converts to a digit value below the range, reducing the accumulator, and the decoder derives one extra code point and its position from it. The result is deterministic. The XS backend rejects the same label. Net::IDN::Punycode uses this backend wherever the XS does not build. The two backends disagree about what such a label means, so a sender can pick a label that one installation resolves to a name and another rejects.

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

CWE-1286

References

View on NVD

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CVE-2026-80156
Lantronix SLC8000 before firmware v9.7.0.5, EMG8500/EMG7500 before firmware v9.7.0.1, and all firmware versions of SLB882/SLCx-03/SLCx-02 contain a path traversal vulnerability in the web management portal upload endpoint that allows authenticated attackers to write arbitrary data to any location on the device's filesystem, leading to remote code execution. The upload filename validation strips backslash characters but does not subsequently check for forward slashes when a backslash is detected; by supplying a filename containing both characters an attacker writes outside the intended upload directory to any writable path. Attackers can use this vulnerability to achieve complete loss of confidentiality, integrity, and availability on the affected device and potentially impact downstream serial-connected devices.
2026-09-22 · score 9.1
CVE-2026-80155
Lantronix SLC8000 before firmware v9.7.0.5, EMG8500/EMG7500 before firmware v9.7.0.1, and all firmware versions of SLB882/SLCx-03/SLCx-02 contain an authentication bypass vulnerability in the web management portal upload endpoint that allows unauthenticated attackers to read sensitive configuration files and upload files to arbitrary filesystem locations, leading to remote code execution. The web configuration server constructs the session cookie file path using snprintf with a fixed-size buffer; by supplying a cookie value of a specific length an attacker causes the path to truncate at the required delimiter and leverages path traversal to redirect authentication validation to an arbitrary on-disk file such as the local user database, bypassing all session checks. Attackers can use this vulnerability to achieve complete loss of confidentiality, integrity, and availability on the affected device and potentially impact downstream serial-connected devices.
2026-09-22 · score 10.0
CVE-2026-80154
All firmware versions of Lantronix SLC8000, EMG8500, EMG7500, SLB882, SLCx-03, and SLCx-02 contain an authentication bypass vulnerability in the web management portal that allows unauthenticated attackers to derive valid session tokens of logged-in users and bypass source IP and User-Agent validation. Session tokens are generated deterministically from the device model and the current time at one-second resolution, resulting in a small enumerable set of possible active tokens. Attackers can construct a crafted URI that exploits file extension handling in the web server path routing to bypass per-session source-address validation, then use a derived token from a different source address to gain elevated privileges on the affected device and potentially impact downstream serial-attached devices.
2026-09-22 · score 9.6
CVE-2026-80152
Lantronix SLC8000 before firmware v9.7.0.3, EMG8500/EMG7500 before firmware v9.7.0.1, and all firmware versions of SLB882/SLCx-03/SLCx-02 contain a command injection vulnerability that allows authenticated attackers with the services permission to execute arbitrary shell commands as root by exploiting the set script schedule command that passes unsanitized user input to a system() call. Attackers with the services permission can authenticate to the terminal or CLI interface and inject malicious commands through the unsanitized parameter to achieve complete loss of confidentiality, integrity, and availability on the affected device and potentially impact downstream serial-attached devices.
2026-09-22 · score 9.1
CVE-2026-80151
Lantronix SLC8000 before firmware v9.7.0.3, EMG8500/EMG7500 before firmware v9.7.0.1, and all firmware versions of SLB882/SLCx-03/SLCx-02 contain a command injection vulnerability that allows authenticated attackers with the services permission to execute arbitrary shell commands as root by exploiting the set nfs download command that passes unsanitized user input to a system() call. Attackers with the services permission can authenticate to the terminal or CLI interface and inject malicious commands through the unsanitized parameter to achieve complete loss of confidentiality, integrity, and availability on the affected device and potentially impact downstream serial-attached devices.
2026-09-22 · score 9.1