sail: Heap-based Buffer Overflow
CVE-2026-54626 is a critical-severity heap-based buffer overflow vulnerability in sail from HappySeaFox, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected sail versions: < 1.0.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.78% chance of exploitation within 30 days, higher than 56% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of sail you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| HappySeaFox | sail | < 1.0.0 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (github.com).
Official description
SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. In 0.9.10 and earlier, the TGA_INDEXED_RLE path selected by image_type == 9 allocates an image buffer using the one-byte-per-pixel SAIL_PIXEL_FORMAT_BPP8_INDEXED format returned by tga_private_sail_pixel_format() in src/sail-codecs/tga/helpers.c, while sail_codec_load_frame_v8_tga() in src/sail-codecs/tga/tga.c derives a two-to-four-byte pixel_size from an attacker-controlled header bpp value from 9 through 32. Loading a crafted color-mapped run-length-encoded TGA through sail_load_from_file() or sail_load_from_memory() therefore writes attacker-controlled bytes beyond the heap pixel buffer. The pixel-count clamp added for CVE-2026-40494 does not constrain the per-pixel write width, so this issue is an incomplete fix of that vulnerability and can cause heap corruption, a reliable crash, or potential code execution. This issue is fixed in version 1.0.0.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Heap-based Buffer Overflow
The product writes past the end of a buffer that was allocated on the heap.
How developers prevent this class of flaw
- Pre-design: Use a language or compiler that performs automatic bounds checking.
- Use an abstraction library to abstract away risky APIs. Not a complete solution.
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other vulnerabilities in sail
- 7.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
Recent Heap-based Buffer Overflow vulnerabilities
- 8.8 High severity
- 7.1 High severity
- 7.2 High severity
- 7.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
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