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Fencer Intel
medium 6.1

CVE-2011-3656 json

Cross-site scripting (XSS) vulnerability in Mozilla Firefox before 3.6.24 and 4.x through 7 allows remote attackers to inject arbitrary web…

published 2021-06-02 5 y ago modified 2026-06-16 4 mo ago also EUVD-2011-3615

cvss
6.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 55%
public exploits
0
none known

Summary

Cross-site scripting (XSS) vulnerability in Mozilla Firefox before 3.6.24 and 4.x through 7 allows remote attackers to inject arbitrary web script or HTML via vectors involving HTTP 0.9 errors, non-default ports, and content-sniffing.

Patch / fix

  • mozilla firefox 3.6.24

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2011-3656 updated cvss 5.1

Mozilla: Possible XSS via HTTP 0.9 errors and content-sniffing

  • Red Hat Enterprise Linux 4 firefox, seamonkey, thunderbird Red Hat Enterprise Linux 5 firefox, thunderbird Red Hat Enterprise Linux 6 firefox, thunderbird
    affected: no fix available

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.76% chance of exploitation in the next 30 days, higher than 55% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.