CVE-2020-12415

Name: CVE-2020-12415
Creator: NVD / NIST
Published: 2020-07-09T15:15:11.617+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 1.27%

Last modified Jun 17, 2026

CVE-2020-12415 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. When "%2F" was present in a manifest URL, Firefox's AppCache behavior may have become confused and allowed a manifest to be served from a subdirectory. This could cause the appcache to be used to service requests for the top level directory. EPSS estimates a 1.27% chance of exploitation in the next 30 days.

Description

When "%2F" was present in a manifest URL, Firefox's AppCache behavior may have become confused and allowed a manifest to be served from a subdirectory. This could cause the appcache to be used to service requests for the top level directory. This vulnerability affects Firefox < 78.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

1.27%

66.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-276

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 78.0
Opensuse	Leap	15.1
Opensuse	Leap	15.2

References

http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00027.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00049.htmlMailing List, Third Party Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1586630Issue Tracking, Permissions Required, Vendor Advisory
https://security.gentoo.org/glsa/202007-10Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2020-24/Vendor Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00027.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00049.htmlMailing List, Third Party Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1586630Issue Tracking, Permissions Required, Vendor Advisory
https://security.gentoo.org/glsa/202007-10Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2020-24/Vendor Advisory

Timeline

Published: Jul 9, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-12415?

How severe is CVE-2020-12415?

CVE-2020-12415 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 1.27% probability of exploitation in the next 30 days.

How do I fix CVE-2020-12415?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-12415?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST