CVE-2023-5173

7.5 highEPSS 0.9%

High (7.5) in mozilla firefox. EPSS 0.9% chance of exploitation in the next 30 days.

In a non-standard configuration of Firefox, an integer overflow could have occurred based on network traffic (possibly under influence of a local unprivileged webpage), leading to an out-of-bounds write to privileged process memory. *This bug only affects Firefox if a non-standard preference allowing non-HTTPS Alternate Services (`network.http.altsvc.oe`) is enabled.* This vulnerability affects Firefox < 118.

Severity

CVSS 3.1

7.5 high

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS: 0.9% chance of exploitation in the next 30 days; higher than 60% of CVEs (scores of 2026-10-31)
CWE: CWE-190
Published: 2023-09-27
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

mozilla:firefox

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1823172
https://security.gentoo.org/glsa/202401-10
https://www.mozilla.org/security/advisories/mfsa2023-41/
https://bugzilla.mozilla.org/show_bug.cgi?id=1823172
https://security.gentoo.org/glsa/202401-10

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