CVE
FrankenPHP memory disclosure and crash via SplTempFileObject streams
Affects FrankenPHP before 1.13.4 running in worker mode when SplTempFileObject or SplFileObject objects on php://temp persist across worker requests. Fixed in 1.13.4.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N
- Exploited
- No known exploitation
- Fix
- Fixed in 1.13.4
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 1.13.4.
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- FIRST's estimate of the chance attackers exploit it in the next 30 days, updated daily.What do these mean? →
- 0.42% · 37th percentile
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 42/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Unclear
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: partial
Summary
FrankenPHP before 1.13.4 contains a use-after-free vulnerability in worker mode that frees internal streams of SplTempFileObject or SplFileObject on php://temp instances surviving across requests. Remote clients can send requests reaching code that uses such persisted objects, causing reads of freed memory that leak garbage data or crash the process.
Who should check
Teams running FrankenPHP before 1.13.4 in worker mode that keep SplTempFileObject or SplFileObject('php://temp') instances across requests.
“Affecting frankenphp >= 0, < 1.13.4”
cve.now Index
- Exploitation0/40No signal
- Exposure17/25No login or user action needed, reachable over the network without a login · Unknown: Advisories don't say whether default setups are affected
- Reach17/20Affects PHP (a widely deployed server, runtime, framework or database)
- Severity8.3/10CVSS 8.3
- No patch0/5No signal
What would change the score
- Would score about 87 if added to CISA KEV
- Would score about 82 if CISA's SSVC rates exploitation active
- Would score about 47 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 1.13.4.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-128016 (FrankenPHP before 1.13.4 Use-After-Free of SplTempFileObject Streams in Worker Mode), using the cve.now data below.
Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.
What cve.now has for CVE-2026-128016 (entry last updated 2026-11-13):
Affected:
- php frankenphp: fixed in 1.13.4
Fixed versions: 1.13.4.
Conditions (all must be true for the bug to be hit):
- Worker mode is in use. (source: https://github.com/php/frankenphp/security/advisories/GHSA-cm3q-jw2q-9rh5)
- A SplTempFileObject or SplFileObject on php://temp object survives across worker requests, kept on purpose or left in an uncollected reference cycle. (source: https://github.com/php/frankenphp/security/advisories/GHSA-cm3q-jw2q-9rh5)
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
Attacker needs: network access, no login, no user action.
CISA KEV: CVE-2026-128016 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-128016 only. If you also check another CVE, look up its own KEV status; never assume it from this one.
How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.
Verify against the linked advisories before concluding, and cite the date you read each one:
- https://github.com/php/frankenphp/security/advisories/GHSA-cm3q-jw2q-9rh5
- https://github.com/php/frankenphp/commit/837b76880b33a1a78ae4f27dea85bdcddb6cf70c
- https://www.vulncheck.com/advisories/frankenphp-before-1.13.4-use-after-free-of-spltempfileobject-streams-in-worker-mode
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.
Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.
Entry: https://cve.now/CVE-2026-128016
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-128016"}.Timeline
- CVE published
- First seen by cve.now
- Posted on X by cve.now
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- php frankenphp
fixed in 1.13.4
Evidence 5
Vendor advisory · 1
Establishes: Affected and fixed versions.
- Advisory
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-128016
Is CVE-2026-128016 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: cve.now feed data
What does this mean?
In worker mode, FrankenPHP frees the internal stream of a SplTempFileObject or SplFileObject on php://temp that survives a request boundary. Later reads of that freed memory can leak garbage data or crash the whole FrankenPHP process.Source: github.com, vulncheck.com
Which versions are affected by CVE-2026-128016?
frankenphp: before 1.13.4.Source: cve.now feed data
Am I affected, and how do I check?
FrankenPHP versions before 1.13.4 that run in worker mode are affected, but only where such an object survives across worker requests, either kept on purpose or left in an uncollected reference cycle. To check, look at the installed FrankenPHP version and whether worker mode is in use.Source: github.com, vulncheck.com
How do I fix CVE-2026-128016?
Upgrade FrankenPHP to 1.13.4 or later, which is the fixed version. The facts name no vendor patch ids.Source: github.com, vulncheck.com