CVE
FrankenPHP out-of-bounds write in bundled Brotli decoder
Affects FrankenPHP standalone static binaries 1.8.0 to 1.13.1 when an app passes attacker-controlled data to brotli_uncompress_add(). Fixed in 1.13.2.
Written by anthropic/claude-sonnet-5.5 from the sources below. Verify against them.
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- Exploited
- Public exploit code, no confirmed attacks
- Fix
- Fixed in 1.13.2
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 1.13.2.
- 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? →
- First public exploit on GitHub Nov 14
- Last checked
- FIRST's estimate of the chance attackers exploit it in the next 30 days, updated daily.What do these mean? →
- 0.75% · 55th 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? →
- 65/100 · 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? →
- 1 proof of concept on GitHub
Summary
FrankenPHP's standalone static binaries bundle a Brotli decoder with an out-of-bounds write, which a remote attacker with no login can trigger by sending crafted data to an application that passes it to brotli_uncompress_add(), crashing the whole FrankenPHP process. The write could also allow memory disclosure or code execution (not demonstrated against FrankenPHP), and the bug needs a non-default setup in which the application feeds attacker-controlled data to that function.
Original description
FrankenPHP standalone static binaries 1.8.0 before 1.13.2 bundle the PHP brotli extension statically linked with Brotli 1.2.0, whose decoder contains an out-of-bounds write (CVE-2026-111497). Unauthenticated remote attackers can send crafted data to applications that pass it to brotli_uncompress_add() to crash the entire FrankenPHP process, and possibly cause memory disclosure or code execution.
Who should check
Teams running FrankenPHP standalone static binaries 1.8.0 to 1.13.1 whose PHP code passes untrusted data to brotli_uncompress_add() or brotli_uncompress().
Not fixed by: Loading the extension alone is not exploitable; only code passing untrusted data to the decoder is at risk.
“The standalone static binaries of FrankenPHP 1.8.0 to 1.13.1 include the PHP brotli extension, statically linked with Brotli 1.2.0”
cve.now Index
- Exploitation22/40Public exploit on Exploit-DB or GitHub · Unknown: No CISA SSVC exploitation rating yet
- 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)
- Severity9.2/10CVSS 9.2
- No patch0/5No signal
What would change the score
- Would score about 88 if added to CISA KEV
- Would score about 83 if CISA's SSVC rates exploitation active
- Would score about 70 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 1.13.2.
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-2026-128014 (FrankenPHP 1.8.0 before 1.13.2 Out-of-Bounds Write via Bundled Brotli Decoder), 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-2026-128014 (entry last updated 2026-11-13):
Affected:
- php frankenphp: from 1.8.0, fixed in 1.13.2
Fixed versions: 1.13.2.
Conditions (all must be true for the bug to be hit):
- FrankenPHP standalone static binaries 1.8.0 to 1.13.1, which bundle the PHP brotli extension linked with Brotli 1.2.0 (source: https://github.com/php/frankenphp/security/advisories/GHSA-p746-jj3f-94p8)
- The application passes attacker-controlled data to brotli_uncompress_add() (source: https://github.com/php/frankenphp/security/advisories/GHSA-p746-jj3f-94p8)
- Merely loading the extension is not enough to be exploitable (source: https://github.com/php/frankenphp/security/advisories/GHSA-p746-jj3f-94p8)
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-2026-128014 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-128014 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-p746-jj3f-94p8
- https://www.vulncheck.com/advisories/frankenphp-1.8.0-before-1.13.2-out-of-bounds-write-via-bundled-brotli-decoder
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-2026-128014
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-2026-128014"}.Timeline
- CVE published
- First seen by cve.now
- Posted on X by cve.now1 day
- Exploit code on GitHub
googlesky/CVE-2026-128014
Affected versions
- php frankenphp
From 1.8.0 · fixed in 1.13.2
Evidence 5
Vendor advisory · 1
Establishes: Affected and fixed versions.
- Advisory
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Public exploit code · 1
Establishes: Public exploit code exists (Exploit-DB, Metasploit, Nuclei and GitHub).
- Exploit
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-128014
Is CVE-2026-128014 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. Public exploit code exists (a proof of concept on GitHub).Source: cve.now feed data
What does this mean?
The Brotli 1.2.0 decoder bundled in FrankenPHP's brotli extension can write outside its memory bounds. A single unauthenticated request can crash the whole FrankenPHP process. The write may also allow memory disclosure or code execution, which was not demonstrated against FrankenPHP.Source: github.com
Which versions are affected by CVE-2026-128014?
frankenphp: from 1.8.0 before 1.13.2.Source: cve.now feed data
Am I affected, and how do I check?
Standalone static binaries of FrankenPHP 1.8.0 to 1.13.1 are affected. They include the PHP brotli extension statically linked with Brotli 1.2.0. The problem arises only when an application passes attacker-controlled data to brotli_uncompress_add(); loading the extension alone is not enough. To check, look at the FrankenPHP binary's version and whether the application code calls that function.Source: github.com
How do I fix CVE-2026-128014?
Upgrade FrankenPHP to version 1.13.2, which is the fixed version for this range.Source: github.com