Time-of-check Time-of-use (TOCTOU)
Detailed paths
NVD Description
Note: Versions mentioned in the description apply only to the upstream rsync package and not the rsync package as distributed by Ubuntu.
See How to fix? for Ubuntu:20.04 relevant fixed versions and status.
Rsync versions before 3.4.3 contain a time-of-check to time-of-use (TOCTOU) race condition in daemon file handling that allows attackers to redirect file writes outside intended directories by replacing parent directory components with symbolic links. Attackers with write access to a module path can exploit this race condition to create or overwrite arbitrary files, potentially modifying sensitive system files and achieving privilege escalation when the daemon runs with elevated privileges. This vulnerability can only be triggered if the chroot setting is false.
Remediation
Upgrade Ubuntu:20.04 rsync to version 3.1.3-8ubuntu0.9+esm1 or higher.
References
- http://people.ubuntu.com/~ubuntu-security/cve/CVE-2026-29518
- https://github.com/RsyncProject/rsync/pull/895/changes/8471fdd1561049ef5f58df44a1811a50bd9a531d
- https://github.com/RsyncProject/rsync/releases/tag/v3.4.3
- https://www.vulncheck.com/advisories/rsync-toctou-race-condition-allows-symlink-based-arbitrary-file-write
- https://michael.stapelberg.ch/posts/2026-05-24-minimal-memory-safe-go-rsync-vulns/
- https://access.redhat.com/errata/RHSA-2026:26332
- https://access.redhat.com/errata/RHSA-2026:26408
- https://access.redhat.com/errata/RHSA-2026:26410
- https://access.redhat.com/errata/RHSA-2026:29197
- https://access.redhat.com/security/cve/CVE-2026-29518
- https://bugzilla.redhat.com/show_bug.cgi?id=2469055
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-29518.json
- https://access.redhat.com/errata/RHSA-2026:54769
Out-of-bounds Read
Detailed paths
NVD Description
Note: Versions mentioned in the description apply only to the upstream rsync package and not the rsync package as distributed by Ubuntu.
See How to fix? for Ubuntu:20.04 relevant fixed versions and status.
Rsync version 3.4.2 and prior contain an integer overflow vulnerability in the compressed-token decoder where a 32-bit signed counter is not checked for overflow, allowing a malicious sender to trigger an overflow that causes the receiver process to read and return data from outside the intended buffer bounds. Attackers can exploit this vulnerability to disclose process memory contents including environment variables, passwords, heap and stack data, and library memory pointers, significantly reducing ASLR effectiveness and facilitating further exploitation.
Remediation
Upgrade Ubuntu:20.04 rsync to version 3.1.3-8ubuntu0.9+esm1 or higher.
References
- http://people.ubuntu.com/~ubuntu-security/cve/CVE-2026-43618
- https://github.com/RsyncProject/rsync/releases/tag/v3.4.3
- https://github.com/RsyncProject/rsync/security/advisories/GHSA-g37v-g3gj-pmwq
- https://www.vulncheck.com/advisories/rsync-integer-overflow-information-disclosure
- https://access.redhat.com/errata/RHSA-2026:26332
- https://access.redhat.com/errata/RHSA-2026:26408
- https://access.redhat.com/errata/RHSA-2026:26410
- https://access.redhat.com/errata/RHSA-2026:29197
- https://access.redhat.com/security/cve/CVE-2026-43618
- https://bugzilla.redhat.com/show_bug.cgi?id=2469054
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-43618.json
CVE-2026-45447
Detailed paths
NVD Description
Note: Versions mentioned in the description apply only to the upstream openssl package and not the openssl package as distributed by Ubuntu.
See How to fix? for Ubuntu:20.04 relevant fixed versions and status.
Issue summary: A specially crafted PKCS#7 or S/MIME signed message could trigger a use-after-free during PKCS#7 signature verification.
Impact summary: A use-after-free may result in process crashes, heap corruption, or potentially remote code execution.
When processing a PKCS#7 or S/MIME signed message, if the SignedData digestAlgorithms field is present as an empty ASN.1 SET, OpenSSL may incorrectly free a caller-owned BIO during PKCS7_verify(). A subsequent use of the BIO by the calling application results in a use-after-free condition.
In the common case this occurs when the application later calls BIO_free() on the BIO originally passed to PKCS7_verify(). Depending on allocator behavior and application-specific BIO usage patterns, this may result in a crash or other memory corruption. In some application contexts this may potentially be exploitable for remote code execution.
Applications that process PKCS#7 or S/MIME signed messages using OpenSSL PKCS#7 APIs may be affected. Applications using the CMS APIs for this processing are not affected.
The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.
Remediation
Upgrade Ubuntu:20.04 openssl to version 1.1.1f-1ubuntu2.24+esm4 or higher.
References
- http://people.ubuntu.com/~ubuntu-security/cve/CVE-2026-45447
- https://github.com/openssl/security/commit/3aad5eb7af4de4ee0633c30a8541a54d9bbde63c
- https://github.com/openssl/security/commit/7d4a980c62258c5910cc883936e0c8dbab4d75a8
- https://github.com/openssl/security/commit/9dfd688ad2290fc5075cacbc9bf0c9a93eefed54
- https://github.com/openssl/security/commit/a541ae8bfe849a30cc885e8780715c0f488e496c
- https://github.com/openssl/security/commit/c505d7559da5d5f9f2c3913c6883a5562ce7273e
- https://github.com/openssl/openssl/commit/3aad5eb7af4de4ee0633c30a8541a54d9bbde63c
- https://github.com/openssl/openssl/commit/7d4a980c62258c5910cc883936e0c8dbab4d75a8
- https://github.com/openssl/openssl/commit/9dfd688ad2290fc5075cacbc9bf0c9a93eefed54
- https://github.com/openssl/openssl/commit/a541ae8bfe849a30cc885e8780715c0f488e496c
- https://github.com/openssl/openssl/commit/c505d7559da5d5f9f2c3913c6883a5562ce7273e
- https://openssl-library.org/news/secadv/20260609.txt
- https://access.redhat.com/errata/RHSA-2026:25237
- https://access.redhat.com/errata/RHSA-2026:25239
- https://access.redhat.com/errata/RHSA-2026:26275
- https://access.redhat.com/errata/RHSA-2026:26319
- https://access.redhat.com/errata/RHSA-2026:29197
- https://access.redhat.com/errata/RHSA-2026:34102
- https://access.redhat.com/errata/RHSA-2026:35869
- https://access.redhat.com/errata/RHSA-2026:36215
- https://access.redhat.com/errata/RHSA-2026:36217
- https://access.redhat.com/errata/RHSA-2026:39009
- https://access.redhat.com/errata/RHSA-2026:39012
- https://access.redhat.com/errata/RHSA-2026:39981
- https://access.redhat.com/security/cve/CVE-2026-45447
- https://bugzilla.redhat.com/show_bug.cgi?id=2481898
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-45447.json
- https://access.redhat.com/errata/RHSA-2026:44438
- https://access.redhat.com/errata/RHSA-2026:47735
- https://access.redhat.com/errata/RHSA-2026:47737
- https://access.redhat.com/errata/RHSA-2026:58563
- https://access.redhat.com/errata/RHSA-2026:58981
- https://access.redhat.com/errata/RHSA-2026:59831
Out-of-bounds Write
Detailed paths
NVD Description
Note: Versions mentioned in the description apply only to the upstream gnupg2 package and not the gnupg2 package as distributed by Ubuntu.
See How to fix? for Ubuntu:20.04 relevant fixed versions and status.
In GnuPG before 2.4.9, armor_filter in g10/armor.c has two increments of an index variable where one is intended, leading to an out-of-bounds write for crafted input. (For ExtendedLTS, 2.2.51 and later are fixed versions.)
Remediation
Upgrade Ubuntu:20.04 gnupg2 to version 2.2.19-3ubuntu2.5+esm1 or higher.
References
- http://people.ubuntu.com/~ubuntu-security/cve/CVE-2025-68973
- https://github.com/gpg/gnupg/blob/ff30683418695f5d2cc9e6cf8c9418e09378ebe4/g10/armor.c#L1305-L1306
- https://github.com/gpg/gnupg/commit/115d138ba599328005c5321c0ef9f00355838ca9
- https://github.com/gpg/gnupg/compare/gnupg-2.2.50...gnupg-2.2.51
- https://media.ccc.de/v/39c3-to-sign-or-not-to-sign-practical-vulnerabilities-i
- https://news.ycombinator.com/item?id=46403200
- https://www.openwall.com/lists/oss-security/2025/12/28/5
- http://www.openwall.com/lists/oss-security/2025/12/29/11
- https://lists.debian.org/debian-lts-announce/2026/01/msg00008.html
- https://gpg.fail/memcpy
Race Condition Enabling Link Following
Detailed paths
Overview
Affected versions of this package are vulnerable to Race Condition Enabling Link Following due to insufficient checks when bind-mounting /dev/pts/$n to /dev/console inside the container. An attacker can gain unauthorized write access to sensitive files within the container environment by manipulating the timing of mount operations and providing a malicious configuration, potentially leading to denial of service or container escape.
Note:
This is only exploitable if the attacker can supply a crafted container configuration and execute processes with sufficient privileges inside the container.
Workaround
This vulnerability can be mitigated by:
Using containers with user namespaces enabled.
Configuring containers to not permit processes to run with root privileges.
Applying SELinux policies that restrict access to
/dev/console.
Remediation
Upgrade github.com/opencontainers/runc/libcontainer/system to version 1.2.8, 1.3.3, 1.4.0-rc.3 or higher.
References
- GitHub Commit
- GitHub Commit
- GitHub Commit
- GitHub Commit
- GitHub Commit
- GitHub Commit
- GitHub Commit
- GitHub Commit
Race Condition Enabling Link Following
Detailed paths
Overview
Affected versions of this package are vulnerable to Race Condition Enabling Link Following in the handling of procfs file writes. An attacker can cause arbitrary writes to sensitive files or trigger a denial of service by redirecting write operations through race conditions and manipulating shared mounts or symbolic links. This can result in bypassing security mechanisms, escalating privileges, or crashing the host system by targeting files such as /proc/sysrq-trigger or altering kernel parameters.
Workaround
This vulnerability can be mitigated by:
Do not run untrusted container images from unknown or unverified sources.
Using rootless containers.
Remediation
Upgrade github.com/opencontainers/runc/libcontainer/system to version 1.2.8, 1.3.3, 1.4.0-rc.3 or higher.
References
- GitHub Commit
- GitHub Commit
- GitHub Commit
- GitHub Commit
- GitHub Commit
- GitHub Commit
- GitHub Commit
- GitHub Commit
- GitHub Commit
- GitHub Commit
- GitHub Commit
- GitHub Commit
- GitHub Commit
- GitHub Commit
- GitHub Commit
- GitHub Commit
- GitHub Commit
- GitHub PR
- PoC in GitHub