CVE-2026-58082: Stack based buffer overflow in iconv(3)
The ISO-2022 encoding module used a stack buffer sized to MBLENMAX (6 bytes) for intermediate character output. Some ISO-2022 variants can require up to 10 bytes per character, in which case conversions can trigger a stack buffer overflow of up to four bytes.
An application that uses iconv(3) to convert untrusted input to or from one of the affected encodings may be vulnerable to buffer overflows if it uses one of the affected encoding modules.
Event History
Frequently Asked Questions
Which applications are exposed to this issue?
Applications may be exposed if they use iconv(3) to convert untrusted input to or from an affected ISO-2022 encoding module. The issue is tied to conversions involving ISO-2022 variants that can require more than six bytes for intermediate character output.
What input condition triggers the overflow?
The overflow can occur when an affected ISO-2022 variant requires up to 10 bytes for a character while the module uses a six-byte MB_LEN_MAX stack buffer. This can overwrite up to four bytes on the stack during conversion.
How can I determine whether an application may be affected?
Review whether the application invokes iconv(3) on untrusted data and whether its conversion paths use affected ISO-2022 encoding modules. Applications that do not convert untrusted input to or from those encodings are not described as vulnerable by the available information.