CVE-2025-67269: gpsd_project gpsd Integer Underflow (Wrap or Wraparound)

Vulnerability summary

CVE-2025-67269 is a high (CVSS 7.5) Integer Underflow (Wrap or Wraparound) vulnerability in gpsd_project gpsd. EPSS estimates a 0.56% chance of exploitation in the next 30 days, higher than 45.9% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 02-01-2026
   PublishedVulnerability first disclosed.
2. 15-07-2026
   Last modifiedVulnerability information updated.

Description

An integer underflow vulnerability exists in the `nextstate()` function in `gpsd/packet.c` of gpsd versions prior to commit `ffa1d6f40bca0b035fc7f5e563160ebb67199da7`. When parsing a NAVCOM packet, the payload length is calculated using `lexer->length = (size_t)c - 4` without checking if the input byte `c` is less than 4. This results in an unsigned integer underflow, setting `lexer->length` to a very large value (near `SIZE_MAX`). The parser then enters a loop attempting to consume this massive number of bytes, causing 100% CPU utilization and a Denial of Service (DoS) condition.

• CWE-191Integer Underflow (Wrap or Wraparound)The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.