Patchfirst
CVE-2025-2857 Critical · 10.0 EPSS 2.0%

Incorrect handle could lead to sandbox escapes

Mozilla · Firefox

Official description · CVE.org

Following the recent Chrome sandbox escape (CVE-2025-2783), various Firefox developers identified a similar pattern in our IPC code. A compromised child process could cause the parent process to return an unintentionally powerful handle, leading to a sandbox escape. The original vulnerability was being exploited in the wild. *This only affects Firefox on Windows. Other operating systems are unaffected.*. This vulnerability was fixed in Firefox 136.0.4, Firefox ESR 128.8.1, and Firefox ESR 115.21.1.

Breakdown
64.7 / 100
Exploited
Yes, in VulnCheck KEV
Reports
0
Tactics
0/15

First seen exploited 10 months after disclosure.

  1. Disclosedday 0
  2. First seen exploitedVulnCheck KEV evidence+10 mo

techniques

No techniques linked

No ATT&CK techniques are linked to this CVE yet. MITRE CTID has not mapped it, and no report passage in the corpus ties it to a technique.

What security researchers reported

Not named in any threat report yet

Also mentioned in 4 community threat pulses (AlienVault OTX)

Weaker evidence

Pulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.

References

4 links, grouped by NVD tag
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