CVE-2026-40930 (GCVE-0-2026-40930)
Vulnerability from cvelistv5 – Published: 2026-06-04 14:34 – Updated: 2026-06-04 16:37
VLAI
EPSS
VEX
Title
LIBPNG: Chunk smuggling in push-mode APNG parser via unconsumed chunk body
Summary
LIBPNG is a reference library for use in applications that process PNG (Portable Network Graphics) raster image files. In version 1.8.0, three inter-frame chunk discard paths in the push-mode APNG parser clear the chunk-header flag without consuming the chunk body and CRC, allowing attacker-controlled bytes inside an ignored ancillary chunk to be reinterpreted as a fresh chunk header on the next call to `png_process_data`. Commit faf06924688b62d7c1654b5ceddedbde66ffadb4 fixes the issue.
Severity
5.4 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-436 - Interpretation Conflict
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/pnggroup/libpng/security/advis… | x_refsource_CONFIRM |
| https://github.com/pnggroup/libpng/commit/faf0692… | x_refsource_MISC |
| http://www.openwall.com/lists/oss-security/2026/0… |
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| pnggroup | libpng |
Affected:
= 1.8.0
|
|
| pnggroup | libpng-apng |
Affected:
>= 1.6.49, <= 1.6.57
|
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
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