The vulnerability originates from an integer underflow in the CFE_SB_GetUserDataLength function, which can be triggered by manipulating the TotalMsgSize and HdrSize arguments. The underflow causes an incorrect data length to be reported, which may lead to software misbehavior, resource exhaustion, or denial of service if exploited by an attacker. The flaw does not directly provide code execution but enables a remote attacker to disrupt system operation by sending crafted messages.

The flaw affects NASA’s Core Flight System (cFS) component cFE Software Bus in any version up to 7.0.1. Systems using these versions of the cFS codebase may be susceptible if they expose the Software Bus interface to external parties.

The CVSS score of 5.3 indicates moderate overall severity. The EPSS score is not available, and the vulnerability is not listed in CISA KEV. Because exploitation can be performed remotely by sending malformed messages, the attack vector is likely network‑based. Successful exploitation would allow an attacker to induce incorrect length calculations, potentially leading to buffer overrun attempts or service disruption, depending on how the receiving code processes the returned length.