How severe is CVE-2022-26386?

CVE-2022-26386 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2022-26386 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2022-26386?

CVE-2022-26386 primarily affects Mozilla Firefox Esr. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2022-26386?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2022-26386 published?

CVE-2022-26386 was published on 2022-12-22 and last updated on 2026-06-17.

CVE-2022-26386

CVE-2022-26386 is a medium-severity vulnerability in Mozilla Firefox Esr with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-377.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
EPSS exploit prediction: 1% (48th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-377
Affected product: Mozilla Firefox Esr
Published: 2022-12-22
Last modified: 2026-06-17

Description

Previously Firefox for macOS and Linux would download temporary files to a user-specific directory in <code>/tmp</code>, but this behavior was changed to download them to <code>/tmp</code> where they could be affected by other local users. This behavior was reverted to the original, user-specific directory. <br>*This bug only affects Firefox for macOS and Linux. Other operating systems are unaffected.*. This vulnerability affects Firefox ESR < 91.7 and Thunderbird < 91.7.

Frequently asked questions

What is CVE-2022-26386?: Previously Firefox for macOS and Linux would download temporary files to a user-specific directory in <code>/tmp</code>, but this behavior was changed to download them to <code>/tmp</code> where they could be affected by other local users. This behavior was reverted to the original, user-specific directory. <br>*This bug only affects Firefox for macOS and Linux. Other operating systems are unaffected.*. This vulnerability affects Firefox ESR < 91.7 and Thunderbird < 91.7.
How severe is CVE-2022-26386?: CVE-2022-26386 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2022-26386 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2022-26386?: CVE-2022-26386 primarily affects Mozilla Firefox Esr. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2022-26386?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2022-26386 published?: CVE-2022-26386 was published on 2022-12-22 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*

More vulnerabilities in Mozilla Firefox Esr

CVE-2021-4140 — Critical (CVSS 10.0): It was possible to construct specific XSLT markup that would be able to bypass an iframe sandbox. This vulnerability…
CVE-2021-38503 — Critical (CVSS 10.0): The iframe sandbox rules were not correctly applied to XSLT stylesheets, allowing an iframe to bypass restrictions such…
CVE-2020-12389 — Critical (CVSS 10.0): The Firefox content processes did not sufficiently lockdown access control which could result in a sandbox escape.…
CVE-2020-12388 — Critical (CVSS 10.0): The Firefox content processes did not sufficiently lockdown access control which could result in a sandbox escape.…
CVE-2015-2740 — Critical (CVSS 10.0): Buffer overflow in the nsXMLHttpRequest::AppendToResponseText function in Mozilla Firefox before 39.0, Firefox ESR 31.x…
CVE-2015-2739 — Critical (CVSS 10.0): The ArrayBufferBuilder::append function in Mozilla Firefox before 39.0, Firefox ESR 31.x before 31.8 and 38.x before…

All CVEs affecting Mozilla Firefox Esr →

Other CWE-377 (Insecure Temporary File) vulnerabilities

CVE-2011-4119 — Critical (CVSS 9.8): caml-light <= 0.75 uses mktemp() insecurely, and also does unsafe things in /tmp during make install.
CVE-2012-2666 — Critical (CVSS 9.8): golang/go in 1.0.2 fixes all.bash on shared machines. dotest() in src/pkg/debug/gosym/pclntab_test.go creates a…
CVE-2015-5224 — Critical (CVSS 9.8): The mkostemp function in login-utils in util-linux when used incorrectly allows remote attackers to cause file name…
CVE-2025-14307 — High (CVSS 8.1): An insecure temporary file creation vulnerability exists in the AutoExtract component of Robocode version 1.9.3.6. The…
CVE-2023-43498 — High (CVSS 8.1): In Jenkins 2.423 and earlier, LTS 2.414.1 and earlier, processing file uploads using MultipartFormDataParser creates…
CVE-2025-46369 — High (CVSS 7.8): Dell Alienware Command Center 6.x (AWCC), versions prior to 6.10.15.0, contains an Insecure Temporary File…

Browse all CWE-377 (Insecure Temporary File) vulnerabilities →