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TI-2026-27001 Aliases CVE-2026-34757

Use after free in pnggroup libpng

Priority MEDIUM 56CWE-416Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
Low · Low · None
Fix status
Partial Red Hat: 1 fixed, 11 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. From 1.0.9 to before 1.6.57, passing a pointer obtained from png_get_PLTE, png_get_tRNS, or png_get_hIST back into the corresponding setter on the same png_struct/png_info pair causes the setter to read from freed memory and copy its contents into the replacement buffer. The setter frees the internal buffer before copying from the caller-supplied pointer, which now dangles. The freed region may contain stale data (producing silently corrupted chunk metadata) or data from subsequent heap allocations (leaking unrelated heap contents into the chunk struct). This vulnerability is fixed in 1.6.57.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00199 9th percentileScored 2026-11-07
Public exploit Yes 2 exploit referencesTagged by NVD
Fix Partial libpng (pnggroup): 1.6.57Red Hat: 1 advisoryRed Hat: 1 fixed, 11 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
pnggrouplibpng1.0.9 to before 1.6.571.6.57Patch availableCNA
  • libpng Vendorpnggroup Affected 1.0.9 to before 1.6.57 Fixed in 1.6.57 Patch available CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:libpng:libpng:*:*:*:*:*:*:*:*1.0.9 to before 1.6.57Vulnerablepnggroup
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*11.0VulnerableDebian
  • cpe:2.3:a:libpng:libpng:*:*:*:*:*:*:*:* Versions 1.0.9 to before 1.6.57 Vulnerable ·pnggroup
  • cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Versions 11.0 Vulnerable ·Debian

Remediation

  • Fix · CNA libpng (pnggroup) Fixed in 1.6.57

Red Hat 1 advisory

  • RHSA-2026:13719 Released 2026-05-05 · Red Hat rating Moderate
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images libpng-1.6.57-0.1.hum1@aarch64, libpng-1.6.57-0.1.hum1@src, libpng-1.6.57-0.1.hum1@x86_64 +6

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 6AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 7AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 4AffectedNo fix yet: Fix deferred
Red Hat build of OpenJDK 1.8AffectedNo fix yet: Fix deferred
Red Hat build of OpenJDK 11 ELSAffectedNo fix yet: Fix deferred
Red Hat build of OpenJDK 17AffectedNo fix yet: Fix deferred
Red Hat build of OpenJDK 21AffectedNo fix yet: Fix deferred
Red Hat build of OpenJDK 25AffectedNo fix yet: Fix deferred
Red Hat Hardened ImagesFixed RHSA-2026:13719

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-34757

References

Exploit 2

Patch 3

Advisory 1

  • TI-2011-02683 Integer signedness error in the png_inflate function in pngrutil.c in libpng before… CVSS 3.1HIGH 8.8
  • TI-2010-01161 Buffer overflow in pngpread.c in libpng before 1.2.44 and 1.4.x before 1.4.3, as used in… CVSS 3.1CRITICAL 9.8
  • TI-2026-20746 LIBPNG has a heap buffer overflow in png_set_quantize CVSS 4.0HIGH 8.3
  • TI-2025-40204 LIBPNG is vulnerable to a heap buffer overflow in `png_combine_row` triggered via `png_image_finish_read` CVSS 3.1HIGH 7.1
  • TI-2025-40767 LIBPNG has an out-of-bounds read in png_image_read_composite CVSS 3.1HIGH 7.1
  • TI-2025-40066 LIBPNG is vulnerable to a buffer overflow in `png_image_read_composite` via incorrect palette premultiplication CVSS 3.1HIGH 7.1
See all 56 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences