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High 8.8Published Sep 29, 2026

CVE-2026-100767Use-after-free in the Networking: Cache component

Updated under an hour ago ()

Does this affect you?

It affects Mozilla Firefox and 1 other product. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.32%, higher than 23% of scored CVEs.

Use-after-free in the Networking: Cache component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.

CVSS
8.8 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness (CWE)
CWE-416
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
0.32% (percentile 23)
Assigned by
mozilla
NVD analysis
Analyzed
Record last updated
Sep 30, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
Mozilla Firefox
mozilla:firefox (from the name)
115.42 builds before 115.* not affected; 140.17 builds before 140.* not affected; 153.4 builds before 153.* not affected; from 157 not affected
CNA record
Mozilla Thunderbird
mozilla:thunderbird (from the name)
140.17 builds before 140.* not affected; 153.4 builds before 153.* not affected; from 157 not affected
CNA record
mozilla firefox
mozilla:firefox
from 115.0 before 115.42.0; from 140.0 before 140.17.0; from 153.0.0 before 153.4.0; from 154.0.0 before 157.0.0
NVD
mozilla thunderbird
mozilla:thunderbird
from 140.0 before 140.17.0; from 153.0 before 153.4.0; from 154.0 before 157.0
NVD

References

  • permissions-required
  • vendor-advisory
  • vendor-advisory
  • vendor-advisory
  • vendor-advisory
  • vendor-advisory
  • vendor-advisory
  • vendor-advisory

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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