CVE-2026-128021 json
FrankenPHP before 1.13.2 Information Disclosure via libxml Error State in Worker Mode
published 24d ago modified yesterday also EUVD-2026-125081 , GHSA-4gfw-9v29-gp9h
Unreviewed: the maintainers' own advisory
Published by the maintainers on their GitHub repository php/frankenphp. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.
- cvss
- 3.7
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 20%
- public exploits
- 0
- none known
Summary
FrankenPHP before 1.13.2 contains an information disclosure vulnerability that allows later clients to read earlier clients' libxml errors because worker mode never resets LIBXML(error_list) between requests. Attackers sending requests to the same worker thread can call libxml_get_errors() or libxml_get_last_error() to obtain other clients' parsed-document fragments and server filesystem paths.
Patch / fix
- php frankenphp 1.13.2
Is CVE-2026-128021 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- yesterday
Exploit prediction
0.28% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-14).
Exploits and checks
- github.com https://github.com/php/frankenphp/security/advisories/GHSA-4gfw-9v29-gp9h referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 6.3 | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N |
| CNA | 3.1 | 3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N |
| CNA | 4.0 | 6.3 | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- php frankenphp
Classification
- Weakness
-
- CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
References
-
github.com
/php/frankenphp/security/advisories/GHSA-4gfw-9v29-gp9h
vendor-advisory, exploit, advisory
-
vulncheck.com
/advisories/frankenphp-before-1.13.2-information-disclosure-via-libxml-error-state-in-worker-mode
third-party-advisory
Sources
- CVE List CVE-2026-128021
- NVD CVE-2026-128021
- Maintainer advisory GHSA-4gfw-9v29-gp9h
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
The maintainers of php/frankenphp published their own advisory on GitHub. Reviewed sources take precedence over it.