CVE-2026-104596
Description
A flaw was found in libosmocore. An out-of-bounds read vulnerability in the Global System for Mobile Communications (GSM) 04.80 supplementary-service parser allows for information disclosure. A remote attacker can exploit this flaw by sending specially crafted messages, enabling them to read memory beyond expected buffer boundaries and obtain sensitive information.
Statement
This vulnerability is evaluated as having a Moderate impact because, although malformed network input can trigger out-of-bounds buffer reads remotely without authentication, the risk is confined to unauthorized memory disclosure without granting code execution or system alteration. Additionally, libosmocore is not included or supported in Red Hat Enterprise Linux or other Red Hat enterprise products, preventing exposure in standard supported deployments.
Mitigation
No mitigation is available for shipped Fedora builds beyond updating; the upstream fix is in libosmocore 1.14.2 (commit b6c8c72), which Fedora may update to or backport. Exposure requires an application to process attacker-supplied GSM 04.80 supplementary-service messages (e.g., USSD/SS handling in Osmocom-based networks).
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
An attacker could get secret values such as cryptographic keys, PII, memory addresses, or other information that could be used in additional attacks.
Confidentiality
Technical Impact: Bypass Protection Mechanism
Out-of-bounds memory could contain memory addresses or other information that can be used to bypass ASLR and other protection mechanisms in order to improve the reliability of exploiting a separate weakness for code execution.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker could cause a segmentation fault or crash by causing memory to be read outside of the bounds of the buffer. This is especially likely when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string.
Other
Technical Impact: Varies by Context
The read operation could produce other undefined or unexpected results.
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