CVE-2026-34757

Publication date 9 April 2026

Last updated 18 August 2026

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

5.1 · Medium

Score breakdown

Description

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.

Read the notes from the security team

Status

Package Ubuntu Release Status
libpng 26.04 LTS resolute Not in release
25.10 questing Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
16.04 LTS xenial
Fixed 1.2.54-1ubuntu1.1+esm3
14.04 LTS trusty
Fixed 1.2.50-1ubuntu2.14.04.3+esm2
libpng1.6 26.04 LTS resolute
Not affected
25.10 questing
Fixed 1.6.50-1ubuntu0.5
24.04 LTS noble
Fixed 1.6.43-5ubuntu0.6
22.04 LTS jammy
Fixed 1.6.37-3ubuntu0.5
20.04 LTS focal
Fixed 1.6.37-2ubuntu0.1~esm3
18.04 LTS bionic
Fixed 1.6.34-1ubuntu0.18.04.2+esm3
16.04 LTS xenial
Fixed 1.6.20-2ubuntu0.1~esm4
chromium-browser 26.04 LTS resolute
Not affected
25.10 questing
Not affected
24.04 LTS noble
Not affected
22.04 LTS jammy
Not affected
firefox 26.04 LTS resolute
Not affected
25.10 questing
Not affected
24.04 LTS noble
Not affected
22.04 LTS jammy
Not affected
thunderbird 26.04 LTS resolute
Not affected
25.10 questing
Not affected
24.04 LTS noble
Not affected
22.04 LTS jammy
Not affected

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Notes

mdeslaur

Per the upstream developer Cosmin Truta, the fix for this CVE is 398cbe3d, but 55d20aaa and 2c974860 are also security issues that should be fixed at the same time. The only difference between 1.6.56 and 1.6.57 are those 3 changes, and upstream has requested that resolute be updated to the new version rather than having the fix for this CVE backported.

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
libpng1.6

Severity score breakdown

CVSS version: CVSS v3.0

Base score 5.1 · Medium

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

References

Related Ubuntu Security Notices (USN)

Other references

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