Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.72% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-17347High confidence
pgAdmin 4: OS command injection in MASTER_PASSWORD_HOOK via untrusted username substitution
pgadmin.org · pgAdmin 4
7.7HighCVSS 4.0
Within 7 days
Patch availableHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:High, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs pgadmin.org pgAdmin 4 and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Patch available01
What, why and how
The MASTER_PASSWORD_HOOK setting, introduced in pgAdmin 4 7.2, lets an administrator configure an external command that returns a per-user encryption key, with %u in the configured string replaced by the current user's name. The previous implementation substituted the username directly into the command string and executed the result with subprocess.Popen(..., shell=True). Because the username can originate from an external authentication source (OAuth/OIDC claims, Kerberos, webserver auth) rather than a value pgAdmin fully controls, a username containing shell metacharacters (';', '$()', backticks, pipes, '&&', newlines) allowed an authenticated user to execute arbitrary commands as the pgAdmin service account in any deployment where the configured hook string uses %u. Fix tokenises the trusted, administrator-configured hook string into an argument vector first (using shlex in POSIX-quoting mode, with backslash-escaping disabled so Windows-style paths are not mis-parsed), substitutes the untrusted username into the individual argv elements, and executes with shell=False. The username is therefore always confined to a single argv element; any shell metacharacters it contains are inert. Administrators whose MASTER_PASSWORD_HOOK previously relied on shell features (pipes, redirection, environment-variable expansion, globbing) within the hook string itself must move that logic into the invoked script, since it is no longer interpreted by a shell. This issue affects pgAdmin 4: from 7.2 before 9.17.
What
The MASTER_PASSWORD_HOOK setting, introduced in pgAdmin 4 7.2, lets an administrator configure an external command that returns a per-user encryption key, with %u in the configured string replaced by the current user's name. The previous implementation substituted the username directly into the command string and executed the result with subprocess.Popen(..., shell=True). Because the username can originate from an external authentication source (OAuth/OIDC claims, Kerberos, webserver auth) rather than a value pgAdmin fully controls, a username containing shell metacharacters (';', '$()', backticks, pipes, '&&', newlines) allowed an authenticated user to execute arbitrary commands as the pgAdmin service account in any deployment where the configured hook string uses %u. Fix tokenises the trusted, administrator-configured hook string into an argument vector first (using shlex in POSIX-quoting mode, with backslash-escaping disabled so Windows-style paths are not mis-parsed), substitutes the untrusted username into the individual argv elements, and executes with shell=False. The username is therefore always confined to a single argv element; any shell metacharacters it contains are inert. Administrators whose MASTER_PASSWORD_HOOK previously relied on shell features (pipes, redirection, environment-variable expansion, globbing) within the hook string itself must move that logic into the invoked script, since it is no longer interpreted by a shell. This issue affects pgAdmin 4: from 7.2 before 9.17.
Why
Untrusted input is incorporated into an operating-system command without safe parameter handling.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may execute code or commands in the affected security context.
What
The MASTER_PASSWORD_HOOK setting, introduced in pgAdmin 4 7.2, lets an administrator configure an external command that returns a per-user encryption key, with %u in the configured string replaced by the current user's name. The previous implementation substituted the username directly into the command string and executed the result with subprocess.Popen(..., shell=True). Because the username can originate from an external authentication source (OAuth/OIDC claims, Kerberos, webserver auth) rather than a value pgAdmin fully controls, a username containing shell metacharacters (';', '$()', backticks, pipes, '&&', newlines) allowed an authenticated user to execute arbitrary commands as the pgAdmin service account in any deployment where the configured hook string uses %u. Fix tokenises the trusted, administrator-configured hook string into an argument vector first (using shlex in POSIX-quoting mode, with backslash-escaping disabled so Windows-style paths are not mis-parsed), substitutes the untrusted username into the individual argv elements, and executes with shell=False. The username is therefore always confined to a single argv element; any shell metacharacters it contains are inert. Administrators whose MASTER_PASSWORD_HOOK previously relied on shell features (pipes, redirection, environment-variable expansion, globbing) within the hook string itself must move that logic into the invoked script, since it is no longer interpreted by a shell. This issue affects pgAdmin 4: from 7.2 before 9.17.
Why
Untrusted input is incorporated into an operating-system command without safe parameter handling.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may execute code or commands in the affected security context.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- a network path → Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') → execute code or commands in the affected security context
- Attack surface
- Network
- Privileges required
- Low: a basic authenticated account is required
- User interaction
- None
- Attack complexity
- High: exploitation depends on specific conditions
- Security boundary
- Not a CVSS 4.0 base metric
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-78 ↗
CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'). The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NCommon Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.ATNoneAttack requirements: No additional deployment or execution condition is required.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.VCHighVulnerable-system confidentiality: A successful attack can cause a major loss.VIHighVulnerable-system integrity: A successful attack can cause a major loss.VAHighVulnerable-system availability: A successful attack can cause a major loss.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.- Post-exploitation / living off the land
- After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Patch available
- Affected
- pgAdmin 4: 7.2 < 9.17
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 31 Jul 2026 · Last source change 1 Aug 2026, 03:56 UTC · CWE-78 · Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-51560
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
CVE published
Fixed release or patch reference recorded
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.