CVE-2026-58203VulnerabilityPublished 13 Aug 2026Updated 26 Oct 2026

bump-my-version · pydantic-settings: NestedSecretsSettingsSource follows symlinks outside secrets_dir, enabling local file read and

Affects bump-my-versionSource GCVE Database

Authoritative record:CVE-2026-58203· Medium 5.3

Not known to be exploited · CVSS 5.3 Medium : upgrade to 1.4.1_1 when convenient.

Data as of 26 Oct 2026, 17:57 UTC

CVSS 3.1 base score

5.3Medium

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.4.1_1

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

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

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

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
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: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to 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 6 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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 bump-my-version to 1.4.1_1.

Affected software

Product	Affected	Fixed in
Homebrewbump-my-version`pkg:brew/bump-my-version`Other threats	Affected >=1.2.5 <1.4.1_1	Fixed in 1.4.1_1

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

AI-suggested

Upgrade to pydantic-settings version 1.4.1_1 or later, which fixes the issue by restricting directory traversal to paths within the configured secrets_dir, using a single cycle-safe iterator for size checking and loading, and skipping files whose resolved paths escape the secrets_dir. If upgrading is not immediately possible, ensure that the secrets_dir is fully controlled and not writable or influenced by untrusted users or processes, or disable secrets_nested_subdir to avoid following symlinks.

Description

The pydantic-settings library's NestedSecretsSettingsSource component improperly follows symbolic links inside a configured secrets directory that point outside this directory, allowing local files outside the intended secrets directory to be read into application settings. This behavior bypasses the configured maximum size limit for secrets directories, potentially leading to unintended local file disclosure and resource exhaustion via cyclic symlinks. The vulnerability requires the ability to place symlinks inside the secrets directory and is not remotely exploitable by itself. It affects versions from 1.2.5 up to but not including 1.4.1_1. A fix is available in version 1.4.1_1.

Impact

An attacker or lower-privileged component able to place symbolic links inside the configured secrets directory can cause the application to read arbitrary local files outside the intended secrets directory into its settings, violating confidentiality. Additionally, the size limit protection on the secrets directory can be bypassed, potentially leading to resource exhaustion. This vulnerability does not provide remote code execution or network reachability by itself but can expose sensitive local files if the secrets directory is writable or shared with untrusted parties.

Summary

NestedSecretsSettingsSource reads secret values from files within a configured secrets_dir. When secrets_nested_subdir is enabled, the loader follows symbolic links inside secrets_dir that point outside it, reading external files into settings. The size check for secrets_dir_max_size does not follow symlinks, causing a mismatch that allows reading files outside the directory without triggering size limits. This leads to two issues: unintended local file reads (CWE-22 / CWE-59) and bypass of the size cap (CWE-400). Cyclic symlinks can also cause resource usage amplification. The vulnerability requires write or influence over the secrets directory contents. The issue is fixed in pydantic-settings 1.4.1_1 by enforcing path resolution checks and consistent directory traversal.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 17:57 UTC

Technical details

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