As a catastrophic security flaw, CVE-2026-17566 has severe implications, demanding immediate intervention.
Status: Received on 31 Jul 2026, 16:17 UTC
Published on: 31 Jul 2026, 16:17 UTC
CVSS Release: version 3
f86ef6dc-4d3a-42ad-8f28-e6d5547a5007
Secondary
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CVE-2026-17566: pgAdmin 4's Import/Export Data tool builds a psql \copy (...) command line by interpolating a user-supplied SQL query into a Jinja template and passing the rendered line to psql via --command. To stop an attacker from breaking out of the (...) wrapper, create_import_export_job() (route POST /import_export/job/<sid>, gated only by the ordinary, commonly-granted tools_import_export_data permission) validated the query with a hand-written parenthesis-balance checker, _is_query_parens_balanced(). That checker always treated a backslash before a single quote (\') as escaping the quote, i.e. as if standard_conforming_strings were off. PostgreSQL has defaulted standard_conforming_strings to on since 9.1 (2010), the default on every PostgreSQL version pgAdmin 4 currently supports (13-18); under that default psql's own \copy tokenizer treats \ as an ordinary character, so a single quote immediately after it closes the string literal. A query such as SELECT 'a\') TO PROGRAM 'echo pwned' x' was therefore accepted as "balanced" by pgAdmin's checker (which believed the ) was still inside the string), while psql, run through the actual rendered command line, closes the string at that point and treats the following ) as the end of the wrapping \copy (...) subquery, exposing an attacker-chosen TO PROGRAM '<command>' clause that psql executes via popen() -- independent of a subsequent syntax error later on the same line. This is the same class of bug as CVE-2025-12762/CVE-2025-13780 (RCE via psql meta-command/COPY injection during PLAIN-format dump restore), reached through an independently written defense in a different module (Import/Export Data rather than Restore) that had its own, different logic bug (inverted backslash-escape semantics rather than a BOM-defeated regex anchor). The fix rejects any backslash inside a single-quoted string in the query outright, rather than picking one of the two possible psql interpretations. This is intentionally conservative: because the correct interpretation of \ depends on the target server's standard_conforming_strings setting, which the checker cannot reliably know at validation time, refusing the query is safer than guessing. This issue affects pgAdmin 4: from the introduction of _is_query_parens_balanced() before 9.18.
The exploitability of CVE-2026-17566 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).
CVE-2026-17566 presents an accessible attack vector with minimal effort required. Restricting access controls and implementing security updates are critical to reducing exploitation risks.
A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.
Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.
Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.
Above is the CVSS Sub-score Breakdown for CVE-2026-17566, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.
Below is the Impact Analysis for CVE-2026-17566, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.
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