The fetch() API and navigation incorrectly shared the same cache, as the cache key did not include the optional headers fetch() may contain. Under the correct circumstances, an attacker may have been able to poison the local browser cache by priming it with a fetch() response controlled by the additional headers. Upon navigation to the same URL, the user would see the cached response instead of the expected response. This vulnerability affects Firefox < 123.

References

• https://nvd.nist.gov/vuln/detail/CVE-2024-1554
• https://bugzilla.mozilla.org/show_bug.cgi?id=1816390
• https://www.mozilla.org/security/advisories/mfsa2024-05