VulnerabilityPublished 13 Aug 2026Updated 29 Aug 2026

CVE-2026-16241: PostgreSQL · Integer Underflow

Affects PostgreSQLSource CVE Database V5

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Not known to be exploited · CVSS 3.8 Low · fixed in 18.6 : update PostgreSQL when convenient.

Data as of 12 Nov 2026, 23:24 UTC

CVSS 3.1 base score

3.8Low

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 27% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 18.6, 17.11, 16.15 +3

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:L

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 13 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
PostgreSQL	Affected >=18 <18.6	Fixed in 18.6
PostgreSQL	Affected >=17 <17.11	Fixed in 17.11
PostgreSQL	Affected >=16 <16.15	Fixed in 16.15
PostgreSQL	Affected >=15 <15.19	Fixed in 15.19
PostgreSQL	Affected <14.24	Fixed in 14.24
Postgresqlpostgresql/postgresql`pkg:deb/postgresql/postgresql`Other threats	Affected <14.24 <15.19 <16.15 <17.11 <18.5	Fixed in 14.24 15.19 16.15 17.11 18.5

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Until a patch is confirmed, avoid exposing ECPG clients to untrusted database server administrators or malformed bytea inputs lacking the mandatory prefix.

Description

CVE-2026-16241 is an integer underflow vulnerability in PostgreSQL's ECPG client. It allows a database server administrator to cause a temporary denial of service by sending a malformed bytea value missing the required prefix. This leads to the client overwriting a large memory region, typically resulting in a segmentation fault. In rare cases, it may cause client-specific integrity issues. The vulnerability affects multiple PostgreSQL versions prior to 18.6, 17.11, 16.15, 15.19, and 14.24.

Impact

The primary impact is a temporary denial of service against the ECPG client due to client crashes caused by memory corruption. There is no confidentiality impact, but there is a low integrity impact possibility in rare cases. The vulnerability requires high privileges (database server administrator) and does not involve user interaction.

Summary

This vulnerability involves an integer underflow in the PostgreSQL ECPG client when processing a bytea value that lacks the mandatory prefix. An attacker with database server administrator privileges can exploit this flaw to cause the client to overwrite a large memory region with uncontrolled data. The usual outcome is a crash (SIGSEGV), but there is a potential for integrity impact on the client in rare cases. Affected versions include all releases before PostgreSQL 18.6, 17.11, 16.15, 15.19, and 14.24.

References

postgresql.org/support/security/CVE-2026-16241/ (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 13 Sep 2026, 13:04 UTC

Technical details

References

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