6.1

CVE-2025-11712: mozilla firefox Improper Encoding or Escaping of Output

CVSS: 6.1v3.1MediumModified
AliasesUBUNTU-CVE-2025-11712DEBIAN-CVE-2025-11712CGA-f738-5f4w-fpcx
Published 14-10-2025Last modified 13-04-2026
Open JSON

Vulnerability summary

CVE-2025-11712 is a medium (CVSS 6.1) Improper Encoding or Escaping of Output vulnerability in mozilla firefox. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 11.8% of scored vulnerabilities.

Overall risk
24/100
0100
Low · default modelHow is this calculated?
CVSS score
6.1/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.22%
0%100%
Low · -0.05 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 38 · Related 13
DLA-4335-1DLA-4351-1DSA-6025-1DSA-6040-1MGASA-2025-0246MGASA-2025-0247

Timeline

  1. 14-10-2025
    PublishedVulnerability first disclosed.
  2. 13-04-2026
    Last modifiedVulnerability information updated.

Description

A malicious page could have used the type attribute of an OBJECT tag to override the default browser behavior when encountering a web resource served without a content-type. This could have contributed to an XSS on a site that unsafely serves files without a content-type header. This vulnerability was fixed in Firefox 144, Firefox ESR 140.4, Thunderbird 144, and Thunderbird 140.4.

CVSS metrics

6 scores · 6 sources · 1 version

EPSS trend

Probability

0.22%

Chance of exploitation in the next 30 days

Percentile

12%

Versus all other CVEs

30-day change

-0.05 pp

From 0.27% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.22%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ubuntu8 products
  • mozjs102All versions (No fix recorded)
  • mozjs115All versions (No fix recorded)
  • mozjs38All versions (No fix recorded)
  • mozjs52All versions (No fix recorded)
  • mozjs68All versions (No fix recorded)
Chainguard2 products
  • firefox< 140.4-r0
  • firefox-esr< 140.4-r0
Debian2 products
  • firefox-esr< 140.4.0esr-1~deb12u1 | < 140.4.0esr-1~deb13u1 | < 140.4.0esr-1
  • thunderbird< 1:140.4.0esr-1~deb12u1 | < 1:140.4.0esr-1~deb13u1 | < 1:140.4.0esr-1
Mozilla2 products
Wolfi1 product
  • firefox< 140.4-r0

5 vendors · 15 products

References

14 links
Show all 14 references