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FreeBSD-SA-26:73.caroot                                     Security Advisory
                                                          The FreeBSD Project

Topic:          TLS certificate store update due to eMudhra compromise

Category:       core
Module:         caroot
Announced:      2026-10-21
Affects:        All supported versions of FreeBSD.
Corrected:      2026-10-21 04:42:19 UTC (stable/15, 15.1-STABLE)
                2026-10-21 04:44:35 UTC (releng/15.1, 15.1-RELEASE-p6)
                2026-10-21 04:42:07 UTC (stable/14, 14.5-STABLE)
                2026-10-21 04:44:07 UTC (releng/14.5, 14.5-RELEASE-p3)
                2026-10-21 04:43:22 UTC (releng/14.4, 14.4-RELEASE-p12)

For general information regarding FreeBSD Security Advisories,
including descriptions of the fields above, security branches, and the
following sections, please visit <URL:https://security.FreeBSD.org/>.

I.   Background

The root certificate bundle is the trust store that is used by OpenSSL
programs and libraries to aid in determining whether it should trust a given
TLS certificate.  It is generated from the root certificate list maintained
by Mozilla's Network Security Services (NSS) project.

II.  Problem Description

eMudhra generated several of its TLS intermediate CA certificates using a
flawed procedure that used trivially small private keys.  The keys have been
recovered by several parties and publicly disclosed.  The intermediates are
signed by the "emSign ECC Root CA - G3" root certificate, which was included
in the trusted certificate bundle.

The intermediates have been revoked, but OpenSSL does not check certificate
revocation by default.

The corrected bundle marks "emSign ECC Root CA - G3" as untrusted.  It also
incorporates the other root certificate additions and removals in NSS
3.131.1.

III. Impact

An attacker able to intercept network traffic can use the compromised
keys to issue a certificate that impersonates any TLS server, allowing
the traffic to be read or modified without detection.

IV.  Workaround

The certctl(8) utility manages the trust store.  The affected root
certificate can be marked untrusted manually:

# cp /etc/ssl/certs/14bc7599.0 /usr/share/certs/untrusted/14bc7599.pem
# certctl rehash

The file 14bc7599.0 corresponds to "emSign ECC Root CA - G3" as listed by
`certctl list`.

Software that uses its own trust store is not affected.

V.   Solution

Upgrade your vulnerable system to a supported FreeBSD stable or
release / security branch (releng) dated after the correction date,
and restart all daemons that use OpenSSL, or reboot the system.

Perform one of the following:

1) To update your vulnerable system installed from base system packages:

Systems running a 15.0-RELEASE or later version of FreeBSD on the amd64 or
arm64 platforms, which were installed using base system packages, can be
updated via the pkg(8) utility:

# pkg upgrade -r FreeBSD-base

2) To update your vulnerable system installed from binary distribution sets:

Systems running a RELEASE version of FreeBSD on the amd64 or arm64 platforms
which were not installed using base system packages can be updated via the
freebsd-update(8) utility:

# freebsd-update fetch
# freebsd-update install

Users of FreeBSD Update should ensure that freebsd-update(8) is allowed to
create and delete files.  This is allowed by default.

3) To update your vulnerable system via a source code patch:

The following patches have been verified to apply to the applicable
FreeBSD release branches.

a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.

[FreeBSD 15.1]
# fetch https://security.FreeBSD.org/patches/SA-26:73/caroot-15.patch
# fetch https://security.FreeBSD.org/patches/SA-26:73/caroot-15.patch.asc
# gpg --verify caroot-15.patch.asc

[FreeBSD 14.5]
# fetch https://security.FreeBSD.org/patches/SA-26:73/caroot-14.5.patch
# fetch https://security.FreeBSD.org/patches/SA-26:73/caroot-14.5.patch.asc
# gpg --verify caroot-14.5.patch.asc

[FreeBSD 14.4]
# fetch https://security.FreeBSD.org/patches/SA-26:73/caroot-14.4.patch
# fetch https://security.FreeBSD.org/patches/SA-26:73/caroot-14.4.patch.asc
# gpg --verify caroot-14.4.patch.asc

b) Apply the patch.  Execute the following commands as root:

# cd /usr/src
# patch -E -p0 < /path/to/patch

c) Recompile the operating system using buildworld and installworld as
described in <URL:https://www.FreeBSD.org/handbook/makeworld.html>.

Restart all daemons that use OpenSSL, or reboot the system.

VI.  Correction details

This issue is corrected as of the corresponding Git commit hash in the
following stable and release branches:

Branch/path                             Hash                     Revision
- -------------------------------------------------------------------------
stable/15/                              adab1d807360    stable/15-n286061
releng/15.1/                            10201c02ac78  releng/15.1-n283642
stable/14/                              6853bad2e25a    stable/14-n275372
releng/14.5/                            923a96f4d870  releng/14.5-n274897
releng/14.4/                            091c8ad19f88  releng/14.4-n273796
- -------------------------------------------------------------------------

Run the following command to see which files were modified by a
particular commit:

# git show --stat <commit hash>

Or visit the following URL, replacing NNNNNN with the hash:

<URL:https://cgit.freebsd.org/src/commit/?id=NNNNNN>

To determine the commit count in a working tree (for comparison against
nNNNNNN in the table above), run:

# git rev-list --count --first-parent HEAD

VII. References

<URL:https://emudhra.we-have-a-problem.com>

<URL:https://bugzilla.mozilla.org/show_bug.cgi?id=2083449>

<URL:https://bugzilla.mozilla.org/show_bug.cgi?id=2084101>

The latest revision of this advisory is available at
<URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-26:73.caroot.asc>
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