# CVE-2026-17544: Out-of-bounds write in bccomp() via crafted operand and scale

> Attackers can trigger out-of-bounds writes in PHP's bccomp function via crafted inputs, potentially leading to code execution or crashes.

- **Severity:** High 8.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/AU:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Jul 2026
- **Updated:** 31 Jul 2026
- **Also known as:** BIT-libphp-2026-17544, BIT-php-2026-17544, BIT-php-min-2026-17544, DEBIAN-CVE-2026-17544, MINI-24gv-vmvh-87wj, MINI-59fc-23q6-mvr8, UBUNTU-CVE-2026-17544

## What is CVE-2026-17544?

CVE-2026-17544 is a high-severity memory corruption vulnerability in Php Php, published on 30 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Attacker-provided inputs to bccomp() could lead to an out-of-bounds write with stack and heap corruption in PHP versions from 8.4.* before 8.4.24 and from 8.5.* before 8.5.9.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-17544?

3 open source packages ship an affected version, including libphp, php and php-min. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `libphp` | Bitnami | From 8.4.0 | 8.4.24, 8.5.9 |
| `php` | Bitnami | From 8.4.0 | 8.4.24, 8.5.9 |
| `php-min` | Bitnami | From 8.4.0 | 8.4.24, 8.5.9 |

Products: Php Php.

## How do I fix CVE-2026-17544?

Upgrade libphp to a fixed version for your release line: 8.4.24 or 8.5.9.

## Is CVE-2026-17544 being exploited?

There is no known exploitation of CVE-2026-17544 in the wild and no public exploit code.

Public exploit code:

- CVE-2026-17544 — PHP bcmath bccomp() OOB write (stack smashing). Verified: crash on 8.4.23/8.5.8, fixed in 8.4.24. GHSA-x692-q9x7-8c3f (github_poc): https://github.com/Boreas37/CVE-2026-17544-PoC
- CVE-2026-17544: PHP bcmath OOB write → universal memory-only RCE & disable_functions/open_basedir bypass. Offset-free runtime resolver. Verified on   PHP 8.4.x / 8.5.x. (github_poc): https://github.com/r2qa/CVE-2026-17544

## Other vulnerabilities in Php Php

- [CVE-2012-2688](https://insights.sbomify.com/CVE-2012-2688/): Integer overflow in n/a (critical 10.0)
- [CVE-2012-2376](https://insights.sbomify.com/CVE-2012-2376/): Memory corruption in n/a (critical 10.0)
- [CVE-2011-3268](https://insights.sbomify.com/CVE-2011-3268/): Memory corruption in n/a (critical 10.0)
- [CVE-2009-4143](https://insights.sbomify.com/CVE-2009-4143/): Other in n/a (critical 10.0)
- [CVE-2008-5557](https://insights.sbomify.com/CVE-2008-5557/): Memory corruption in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-17544 and fix it if it is affected.

What it is: CVE-2026-17544 is a high-severity memory corruption vulnerability in Php Php, published on 30 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-17544 in the wild and no public exploit code.

Affected packages and fixed versions:
- libphp (Bitnami): affected from 8.4.0; fixed in 8.4.24, 8.5.9
- php (Bitnami): affected from 8.4.0; fixed in 8.4.24, 8.5.9
- php-min (Bitnami): affected from 8.4.0; fixed in 8.4.24, 8.5.9

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-17544/ (Markdown: https://insights.sbomify.com/CVE-2026-17544/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-17544
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-17544
- OSV: https://osv.dev/vulnerability/CVE-2026-17544

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-17544/
Summaries are generated and may contain mistakes; the official description above is the record.