Amazon Linux 2023 : postgresql17, postgresql17-contrib, postgresql17-llvmjit (ALAS2023-2026-2076)

high Nessus Plugin ID 341882

Synopsis

The remote Amazon Linux 2023 host is missing a security update.

Description

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2026-2076 advisory.

Integer wraparound in PostgreSQL tsvector and tsquery data type functions allows an unprivileged database user to cause the server to undersize an allocation and write out-of-bounds, via crafted large inputs.
This may execute arbitrary code as the operating system user running the database. These types are typically sourced from application logic, not taken from the application's user. Hence, application users attacking the database, through the application as a conduit, are unlikely. CVE-2026-6473 had fixed similar problems. Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected.
(CVE-2026-14662)

Cleartext storage in PostgreSQL pgcrypto disabled ciphers allows a user to recover cleartext, via direct observation of the faulty ciphertext. The OpenSSL version and OpenSSL configuration determine the disabled ciphers. If the application accepts encrypted data as input, decryption will succeed even with the wrong key. This in turn loses the modest protection from the Modification Detection Code (MDC).
Affected functions are pgp_sym_encrypt, pgp_sym_decrypt, pgp_pub_encrypt, pgp_pub_decrypt, pgp_sym_encrypt_bytea, pgp_sym_decrypt_bytea, pgp_pub_encrypt_bytea, and pgp_pub_decrypt_bytea. Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected. (CVE-2026-14663)

Heap buffer overflow in PostgreSQL regexp allows the query author to execute arbitrary code as the operating system user running the database, via text that would not pass encoding validation. This shares heritage with CVE-2026-2006, but this case involved unanticipated data growth when round-tripped through pg_wchar. Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected. (CVE-2026-14664)

Incomplete tracking in PostgreSQL of changes to role membership, role attributes, and database ownership allows a query to continue using cached row-level security policies after those changes require a different policy, via plan reuse. Stale policies continue until some other event invalidates the cache or connection termination ends the session. This permits a user to complete reads and modifications that were recently permitted but now forbidden. An attacker must tailor an attack to a particular application's pattern of privilege removal and role-specific row security policies. Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected. (CVE-2026-14666)

Type confusion regarding input of PostgreSQL ctid data type selectivity estimator allows an object creator to view a calculation derived from the value of an arbitrary 4-byte span of memory, via a chosen non-ctid input. While the calculation loses precision, substantial memory value recovery appears possible.
Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected. (CVE-2026-14668)

Heap buffer overflow in PostgreSQL to_char(timestamptz) allows the party choosing the timezone to execute arbitrary code as the operating system user running the database, via a long POSIX timezone abbreviation.
Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected. (CVE-2026-14669)

Heap buffer overflow in PostgreSQL plperl return of a tied hash allows the function owner to execute arbitrary code as the operating system user running the database, via a crafted function body. Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected. (CVE-2026-14670)

Type confusion in PostgreSQL module refint allows an object creator to execute arbitrary code as the operating system user running the database. The fix for this emerged as a non-security bug report, and the fix appear in the git repository with subject refint: Remove plan cache., without a CVE number.
Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected. (CVE-2026-14671)

Observable response discrepancy in PostgreSQL SCRAM authentication allows an unauthenticated user to test the existence of a user via observing the SCRAM iteration count. This requires the probed user to have a non-default scram_iterations count, because the authentication challenge for a nonexistent user reports the default scram_iterations. Within major versions 16-18, minor versions before PostgreSQL 18.5, 17.11, and 16.15 are affected. Versions before PostgreSQL 16 are unaffected. (CVE-2026-14672)

Buffer over-read in PostgreSQL pg_trgm index picksplit function reads past end of a heap buffer. This might allow a table maintainer to infer limited memory values, via the lossy signal of index split choices. Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected. (CVE-2026-14678)

Stack buffer overflow in PostgreSQL argument name matching allows an object creator to achieve unknown impacts via OUT parameter count. The attack can write only 0x0 and 0x1 bytes. Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected. (CVE-2026-14679)

Type confusion with PostgreSQL internal data type arguments allows any user to execute arbitrary code as the operating system user running the database, via calls to functions with that argument type. Type internal represents a class of mutually-incompatible data structures not intended for access from SQL.
The system intended to prevent such function calls, but this prevention had gaps. Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected. (CVE-2026-14680)

Improper enforcement of message integrity in PostgreSQL GSSAPI support allows a user to negotiate GSSAPI contrary to pg_hba.conf rules, via initial direct TLS connection. Despite a pg_hba.conf that appears to require GSSAPI, the connection may exchange data over TLS encryption alone. If the TLS settings are more permissive than the GSS settings, the connection may continue with lesser protection. Within major versions 17-18, minor versions before PostgreSQL 18.5 and 17.11 are affected. Versions before PostgreSQL 17 are unaffected. (CVE-2026-14681)

SQL injection in PostgreSQL EXTRACT() deparse allows an object owner to execute arbitrary SQL as a superuser via a hostile object definition. Attacks affect expression deparse consumers broadly, including pg_dump, psql commands like \sf, and any similar usage in non-core tools. Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected. (CVE-2026-15741)

Integer wraparound in PostgreSQL fuzzystrmatch allows a user to direct writes to a huge range of addresses, executing arbitrary code as the operating system user running the database, via extreme inputs to SQL function levenshtein() or levenshtein_less_equal(). Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected. (CVE-2026-15742)

Type confusion in PostgreSQL portal/cursor lifecycle allows a user to execute arbitrary code as the operating system user running the database, via re-creation of a cursor or other portal with different types. Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected. (CVE-2026-16239)

Integer underflow in PostgreSQL ECPG allows a database server administrator to achieve temporary denial of service against the ECPG client via sending a byte value lacking the mandatory prefix. The client overwrites a huge memory region with bytes outside attacker knowledge or control. This typically yields a simple SIGSEV, but rare cases might achieve client-specific integrity impact via the write. Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected. (CVE-2026-16241)

Buffer over-read in PostgreSQL ascii() SQL function allows a user to disclose up to 3 bytes after the end of a specific allocation, via a crafted text value. This is the same class of defect that CVE-2026-2006 fixed, though this instance has less impact. Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected. (CVE-2026-18024)

Untrusted data inclusion in pg_dump in PostgreSQL allows a malicious superuser of the origin server to inject arbitrary code for restore-time execution as the client operating system account running psql to restore the dump, via psql \restrict meta-command input expansion. The fix for CVE-2025-8714 introduced \restrict and \unrestrict to block this attack, but \unrestrict itself was sufficient for an attack.
pg_dumpall is also affected. pg_restore is affected when used to generate a plain-format dump. Non-core use of \restrict would be affected, but we've not identified non-core use. Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected. (CVE-2026-18408)

Heap buffer overflow in PostgreSQL pg_dump of long function transform lists allows an object creator to execute arbitrary code as the operating system user running pg_dump, via a crafted transform list.
Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected. (CVE-2026-19385)

Untrusted data inclusion in PostgreSQL psql COPY may allow a server administrator to elicit execution of data lines as psql commands, via error injection. If the COPY FROM STDIN or \copy FROM STDIN command fails before the server indicates that it awaits input rows, psql processes the in-line data rows as psql commands. COPY FROM with a filename is unaffected. The server administrator has no inherent control over the data rows, so a complete attack requires the attacker to separately acquire control of both the server and the data rows. Alternatively, an attacker controlling data rows alone might complete an attack through a coincidental error that they don't control. Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected. (CVE-2026-6464)

Incorrect ownership assignment in PostgreSQL ALTER TABLE ALTER TYPE command reassigns ownership of dependent statistics objects to the current user. This wrongly allows the table owner to run DROP STATISTICS and ALTER STATISTICS via this improper ownership. It wrongly denies those commands to the prior statistics object owner. DROP TABLE remains able to remove statistics objects, so this exploit achieves nothing in many ownership arrangements. Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected. (CVE-2026-6469)

Missing authorization in PostgreSQL DDL commands allows an object creator to achieve denial of service against ALTER and DROP of the type, via creating a dependency on the type. Many DDL operations did check the privilege, but assigning a range subtype and referencing the type from an SQL expression did not.
Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected. (CVE-2026-6470)

Missing authorization in PostgreSQL logical decoding allows a non-superuser holding REPLICATION privilege to dlopen any file visible to the operating system account running the server, via the choice of logical decoding plugin. This in turn runs arbitrary code as that account. Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected. (CVE-2026-6471)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Run 'dnf update postgresql17 --releasever 2023.12.20260831' or or 'dnf update --advisory ALAS2023-2026-2076 --releasever 2023.12.20260831' to update your system.

Plugin Details

Severity: High

ID: 341882

File Name: al2023_ALAS2023-2026-2076.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 8/31/2026

Updated: 8/31/2026

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Nessus Agent, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.17

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2026-18408

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.9

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

CVSS Score Source: CVE-2026-19385

Vulnerability Information

CPE: cpe:/o:amazon:linux:2023, p-cpe:/a:amazon:linux:postgresql17-contrib-debuginfo, p-cpe:/a:amazon:linux:postgresql17-contrib, p-cpe:/a:amazon:linux:postgresql17-debuginfo, p-cpe:/a:amazon:linux:postgresql17-debugsource, p-cpe:/a:amazon:linux:postgresql17-docs-debuginfo, p-cpe:/a:amazon:linux:postgresql17-docs, p-cpe:/a:amazon:linux:postgresql17-llvmjit-debuginfo, p-cpe:/a:amazon:linux:postgresql17-llvmjit, p-cpe:/a:amazon:linux:postgresql17-plperl-debuginfo, p-cpe:/a:amazon:linux:postgresql17-plperl, p-cpe:/a:amazon:linux:postgresql17-plpython3-debuginfo, p-cpe:/a:amazon:linux:postgresql17-plpython3, p-cpe:/a:amazon:linux:postgresql17-pltcl-debuginfo, p-cpe:/a:amazon:linux:postgresql17-pltcl, p-cpe:/a:amazon:linux:postgresql17-private-devel, p-cpe:/a:amazon:linux:postgresql17-private-libs-debuginfo, p-cpe:/a:amazon:linux:postgresql17-private-libs, p-cpe:/a:amazon:linux:postgresql17-server-debuginfo, p-cpe:/a:amazon:linux:postgresql17-server-devel-debuginfo, p-cpe:/a:amazon:linux:postgresql17-server-devel, p-cpe:/a:amazon:linux:postgresql17-server, p-cpe:/a:amazon:linux:postgresql17-static, p-cpe:/a:amazon:linux:postgresql17-test-debuginfo, p-cpe:/a:amazon:linux:postgresql17-test-rpm-macros, p-cpe:/a:amazon:linux:postgresql17-test, p-cpe:/a:amazon:linux:postgresql17-upgrade-debuginfo, p-cpe:/a:amazon:linux:postgresql17-upgrade-devel-debuginfo, p-cpe:/a:amazon:linux:postgresql17-upgrade-devel, p-cpe:/a:amazon:linux:postgresql17-upgrade, p-cpe:/a:amazon:linux:postgresql17

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 8/31/2026

Vulnerability Publication Date: 8/13/2026

Reference Information

CVE: CVE-2026-14662, CVE-2026-14663, CVE-2026-14664, CVE-2026-14666, CVE-2026-14668, CVE-2026-14669, CVE-2026-14670, CVE-2026-14671, CVE-2026-14672, CVE-2026-14678, CVE-2026-14679, CVE-2026-14680, CVE-2026-14681, CVE-2026-15741, CVE-2026-15742, CVE-2026-16239, CVE-2026-16241, CVE-2026-18024, CVE-2026-18408, CVE-2026-19385, CVE-2026-6464, CVE-2026-6469, CVE-2026-6470, CVE-2026-6471

IAVB: 2026-B-0238

Detections

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