Vulnerability · CVE-2026-113399
Incorrect boundary conditions in the SVG component.
Published Oct 20, 2026 · catalog updated Oct 20, 2026 · Mozilla Firefox
Check if you run it
No confirmed exploitation is on record for CVE-2026-113399. EPSS is 0.18%. Act only if a listed version of Mozilla Firefox is installed.
Gaps on this record
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- Unknown—
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.18%
- Remediation
- Advisory link
- Affected products
- vendor Mozilla Firefox · vendor Mozilla Thunderbird
Incorrect boundary conditions in the SVG component. This vulnerability was fixed in Firefox 158.0.1 and Thunderbird 158.0.1.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- vendor Mozilla Firefoxversion unspecified
- vendor Mozilla Thunderbirdversion unspecified
How to fix CVE-2026-113399
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-113399. EPSS is 0.18%. Act only if a listed version of Mozilla Firefox is installed.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
No weakness class is stored. EPSS 0.18%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Oct 20, 2026 · NIST NVD
Detected
Incorrect boundary conditions in the SVG component. This vulnerability was fixed in Firefox 158.0.1.
Oct 20, 2026 · NIST NVD
Updated
Incorrect boundary conditions in the SVG component. This vulnerability was fixed in Firefox 158.0.1 and Thunderbird 158.0.1.
Sources
- BSI CERT-BundGovernment advisoryCVE-2026-113399
Mozilla Produkte (Thunderbird, Firefox ESR und Firefox): Mehrere Schwachstellen
wid.cert-bund.de - CVE.orgVulnerability recordCVE-2026-113399
Incorrect boundary conditions in the SVG component. This vulnerability was fixed in Firefox 158.0.1 and Thunderbird 158.0.1.
cve.org - FIRST EPSSExploitation probabilityCVE-2026-113399
30-day exploitation probability 0.18%
first.org - Mozilla Security AdvisoriesVendor advisoryCVE-2026-113399
Security Vulnerabilities fixed in Thunderbird 158.0.1 — Mozilla
mozilla.org - NIST NVDVulnerability recordCVE-2026-113399
Incorrect boundary conditions in the SVG component. This vulnerability was fixed in Firefox 158.0.1 and Thunderbird 158.0.1.
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 23, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.