CVE-2026-53500Thumbor treats ALLOWED_SOURCES string patterns as unescaped regex, allowing hostname bypass via wildcard dot
- 8.2HighCVSS base score
- 0.50%Exploitation in 30 daysEPSS · top 57% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
Description
Thumbor is an open-source photo thumbnail service by globo.com. Prior to 7.8.0, the ALLOWED_SOURCES configuration passes plain strings to re.match() without escaping dots, so a hostname differing at dot positions can match the allowlist. This issue is fixed in 7.8.0.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits1
References tagged exploit1 reference
- https://github.com/thumbor/thumbor/security/advisories/GHSA-6x26-6r6f-m537 (opens in a new tab)x_refsource_CONFIRMexploit
Timeline
ID reserved
By GitHub_M
- 52 days later
· 52 days later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High8.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L |
| NVDNVD · Deferred | 3.1 | High8.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L |
- EPSS (exploitation in 30 days)
- 0.50% · top 57% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.2.
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- PyPIthumborGHSA-6x26-6r6f-m537 (opens in a new tab)
References
References3
- https://github.com/thumbor/thumbor/security/advisories/GHSA-6x26-6r6f-m537 (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/thumbor/thumbor/commit/68876715350c6c8f49c324e5515e64908830aed7 (opens in a new tab)x_refsource_MISC
- https://github.com/thumbor/thumbor/releases/tag/7.8.0 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-51597 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-6x26-6r6f-m537 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-53500)Record last updated .