Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
The symfony/html-sanitizer package and the symfony/symfony package are affected in versions from 6.1.0 up to (not including) 6.4.40, from 7.0.0 up to 7.4.12, and from 8.0.0 up to 8.0.12. Its URL sanitizer passed Unicode bidirectional formatting characters through into link and media attributes, so a rendered link can display text in a different order from its real destination. The source does not describe the attacker's access requirements. Users should upgrade to 6.4.40, 7.4.12, or 8.0.12, depending on their branch.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 2.3 | Low | 4.0 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0034, the 27th percentile, on 8 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 20 May 2026, 10:21 UTC Published by the maintainers as a GitHub repository advisory
- 31 Oct 2026, 13:58 UTC First seen by agentprime
- 31 Oct 2026, 13:58 UTC Confirmed by OSV
Sources
- GitHub Advisory Database: GHSA-h5vq-qfcg-4m6p
- OSV: GHSA-h5vq-qfcg-4m6p
- github.com/symfony/symfony/security/advisories/GHSA-h5vq-qfcg-4m6p
- github.com/symfony/symfony/commit/743a435e948b897ef2b5564ac438d4beb95d2526
- github.com/FriendsOfPHP/security-advisories/blob/master/symfony/html-sanitizer/CVE-2026-45064.yaml
- github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2026-45064.yaml
- github.com/symfony/symfony
- symfony.com/cve-2026-45064