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Fencer Intel
high 8.8

CVE-2019-11756 json

Improper refcounting of soft token session objects could cause a use-after-free and crash (likely limited to a denial of service).

published 6y ago modified 4mo ago also EUVD-2019-3426

cvss
8.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.5%
EPSS 1.5% chance of exploitation in 30 days, percentile 74%
public exploits
0
none known

Summary

Improper refcounting of soft token session objects could cause a use-after-free and crash (likely limited to a denial of service). This vulnerability affects Firefox < 71.

Patch / fix

  • mozilla firefox 71.0
  • firefox Ubuntu 16.04 LTS 71.0+build5-0ubuntu0.16.04.1
  • firefox Ubuntu 18.04 LTS 71.0+build5-0ubuntu0.18.04.1
  • firefox Ubuntu 20.04 LTS 71.0+build5-0ubuntu1

ubuntu advisories UBUNTU-CVE-2019-11756

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • nss RHEL 7 3.53.1-3.el7_9
  • nspr RHEL 7 4.25.0-2.el7_9
  • nss-util RHEL 7 3.53.1-1.el7_9
  • nss-tools RHEL 7 3.53.1-3.el7_9
  • nss-softokn RHEL 7 3.53.1-6.el7_9
  • nss-sysinit RHEL 7 3.53.1-3.el7_9
  • nss-softokn-freebl RHEL 7 3.53.1-6.el7_9
  • nss RHEL 8 3.53.1-11.el8_2

red hat advisories RHSA-2021:1026RHSA-2021:0876RHSA-2021:0758RHSA-2020:4076RHSA-2020:3280

  • firefox-esr openSUSE Tumbleweed 128.5.1-1.1
  • MozillaFirefox openSUSE Tumbleweed 92.0-1.2

opensuse advisories openSUSE-SU-2024:14572-1openSUSE-SU-2024:10600-1

  • nspr Rocky Linux 8 4.25.0-2.el8_2

rocky linux advisories RLSA-2020:3280

  • firefox Arch Linux 71.0-1

arch linux advisories AVG-1071

Is CVE-2019-11756 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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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-2019-11756 updated cvss 7.1

nss: Use-after-free in sftk_FreeSession due to improper refcounting

  • Red Hat Enterprise Linux 5 nss Red Hat Enterprise Linux 6 nss, nss-tools, nss-sysinit
    affected: no fix planned “Out of support scope”
  • Red Hat OpenShift Do 1 openshiftdo/odo-init-image-rhel7 1.1.3-2
    fixed: vendor fix RHSA-2021:0949
  • Red Hat Enterprise Linux AppStream (v. 8) nspr 4.25.0-2.el8_2, nss 3.53.1-11.el8_2, nss-util 3.53.1-11.el8_2, nss-tools 3.53.1-11.el8_2, nss-softokn 3.53.1-11.el8_2, nss-sysinit 3.53.1-11.el8_2, +1 more
    fixed: vendor fix RHSA-2020:3280
  • Red Hat Enterprise Linux Client (v. 7) nss 3.53.1-3.el7_9, nspr 4.25.0-2.el7_9, nss-util 3.53.1-1.el7_9, nss-tools 3.53.1-3.el7_9, nss-softokn 3.53.1-6.el7_9, nss-sysinit 3.53.1-3.el7_9, +1 more Red Hat Enterprise Linux Client Optional (v. 7) nss-devel 3.53.1-3.el7_9, nspr-devel 4.25.0-2.el7_9, nss-debuginfo 3.53.1-3.el7_9, nspr-debuginfo 4.25.0-2.el7_9, nss-util-devel 3.53.1-1.el7_9, nss-pkcs11-devel 3.53.1-3.el7_9, +4 more
    fixed: vendor fix RHSA-2020:4076
  • Red Hat Enterprise Linux ComputeNode EUS (v. 7.6) nss 3.36.0-9.el7_6, nss-tools 3.36.0-9.el7_6, nss-softokn 3.36.0-7.el7_6, nss-sysinit 3.36.0-9.el7_6, nss-softokn-freebl 3.36.0-7.el7_6
    fixed: vendor fix RHSA-2021:0876
  • Red Hat Enterprise Linux ComputeNode EUS (v. 7.7) nss-softokn 3.44.0-9.el7_7, nss-softokn-freebl 3.44.0-9.el7_7
    fixed: vendor fix RHSA-2021:1026
  • Red Hat Enterprise Linux ComputeNode Optional (v. 7) nss-devel 3.53.1-3.el7_9, nspr-devel 4.25.0-2.el7_9, nss-debuginfo 3.53.1-3.el7_9, nspr-debuginfo 4.25.0-2.el7_9, nss-util-devel 3.53.1-1.el7_9, nss-pkcs11-devel 3.53.1-3.el7_9, +4 more
    fixed: vendor fix RHSA-2020:4076
  • Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.6) nss-devel 3.36.0-9.el7_6, nss-debuginfo 3.36.0-9.el7_6, nss-pkcs11-devel 3.36.0-9.el7_6, nss-softokn-devel 3.36.0-7.el7_6, nss-softokn-debuginfo 3.36.0-7.el7_6, nss-softokn-freebl-devel 3.36.0-7.el7_6
    fixed: vendor fix RHSA-2021:0876
show 10 more
  • Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.7) nss-softokn-devel 3.44.0-9.el7_7, nss-softokn-debuginfo 3.44.0-9.el7_7, nss-softokn-freebl-devel 3.44.0-9.el7_7
    fixed: vendor fix RHSA-2021:1026
  • Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7) nss 3.36.0-9.el7_6, nss-tools 3.36.0-9.el7_6, nss-softokn 3.36.0-7.el7_6, nss-sysinit 3.36.0-9.el7_6, nss-softokn-freebl 3.36.0-7.el7_6 Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7) nss-debuginfo 3.36.0-9.el7_6, nss-pkcs11-devel 3.36.0-9.el7_6
    fixed: vendor fix RHSA-2021:0876
  • Red Hat Enterprise Linux Server (v. 7) nss 3.53.1-3.el7_9, nspr 4.25.0-2.el7_9, nss-util 3.53.1-1.el7_9, nss-tools 3.53.1-3.el7_9, nss-softokn 3.53.1-6.el7_9, nss-sysinit 3.53.1-3.el7_9, +1 more
    fixed: vendor fix RHSA-2020:4076
  • Red Hat Enterprise Linux Server AUS (v. 7.4) nss-softokn 3.28.3-10.el7_4, nss-softokn-freebl 3.28.3-10.el7_4 Red Hat Enterprise Linux Server E4S (v. 7.4) nss-softokn 3.28.3-10.el7_4, nss-softokn-freebl 3.28.3-10.el7_4
    fixed: vendor fix RHSA-2021:0758
  • Red Hat Enterprise Linux Server EUS (v. 7.6) nss 3.36.0-9.el7_6, nss-tools 3.36.0-9.el7_6, nss-softokn 3.36.0-7.el7_6, nss-sysinit 3.36.0-9.el7_6, nss-softokn-freebl 3.36.0-7.el7_6
    fixed: vendor fix RHSA-2021:0876
  • Red Hat Enterprise Linux Server EUS (v. 7.7) nss-softokn 3.44.0-9.el7_7, nss-softokn-freebl 3.44.0-9.el7_7
    fixed: vendor fix RHSA-2021:1026
  • Red Hat Enterprise Linux Server Optional (v. 7) nss-debuginfo 3.53.1-3.el7_9, nss-pkcs11-devel 3.53.1-3.el7_9
    fixed: vendor fix RHSA-2020:4076
  • Red Hat Enterprise Linux Server Optional EUS (v. 7.6) nss-debuginfo 3.36.0-9.el7_6, nss-pkcs11-devel 3.36.0-9.el7_6
    fixed: vendor fix RHSA-2021:0876
  • Red Hat Enterprise Linux Server TUS (v. 7.4) nss-softokn 3.28.3-10.el7_4, nss-softokn-freebl 3.28.3-10.el7_4
    fixed: vendor fix RHSA-2021:0758
  • Red Hat Enterprise Linux Workstation (v. 7) nss 3.53.1-3.el7_9, nspr 4.25.0-2.el7_9, nss-util 3.53.1-1.el7_9, nss-tools 3.53.1-3.el7_9, nss-softokn 3.53.1-6.el7_9, nss-sysinit 3.53.1-3.el7_9, +1 more Red Hat Enterprise Linux Workstation Optional (v. 7) nss-debuginfo 3.53.1-3.el7_9, nss-pkcs11-devel 3.53.1-3.el7_9
    fixed: vendor fix RHSA-2020:4076

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

1.49% chance of exploitation in the next 30 days, higher than 74% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected products

  • Mozilla Firefox

Classification

Weakness

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.