CVE catalog

CVE-2026-33019

libsixel is a SIXEL encoder/decoder implementation…

[CVE catalog]

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain an integer overflow leading to an out-of-bounds heap read in the --crop option handling of img2sixel, where positive coordinates up to INT_MAX are accepted without overflow-safe bounds checking. In sixel_encoder_do_clip(), the expression clip_w + clip_x overflows to a large negative value when clip_x is INT_MAX, causing the bounds guard to be skipped entirely, and the unclamped coordinate is passed through sixel_frame_clip() to clip(), which computes a source pointer far beyond the image buffer and passes it to memmove(). An attacker supplying a specially crafted crop argument with any valid image can trigger an out-of-bounds read in the heap, resulting in a reliable crash and potential information disclosure. This issue has been fixed in version 1.8.7-r1.

Severity
High · CVSS 7.1CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
Published
Source
[NVD] · [CVE record]
EPSS
0.26% · Oct 27, 2026

Projects and upstream resources

Reported versions and fixes

Each observation applies to its named package, distribution, and release. Distribution backports can fix a vulnerability while retaining an older upstream version number.

Version impact has not been established. The original provider fields are retained below.

Provider details and historical evidence
Original provider fields
{
  "package_releases": [
    {
      "name": "libsixel",
      "status": "fixed",
      "release": "sid",
      "version": "1:1.8.7-r2-1"
    },
    {
      "name": "libsixel",
      "status": "fixed",
      "release": "forky",
      "version": "1:1.8.7-r2-1"
    },
    {
      "name": "libsixel",
      "status": "vulnerable",
      "release": "trixie",
      "version": "1.10.5-1"
    },
    {
      "name": "libsixel",
      "status": "vulnerable",
      "release": "bookworm",
      "version": "1.10.3-3"
    }
  ],
  "fixed_versions": [
    {
      "bug": 1136211,
      "name": "libsixel",
      "type": "source",
      "origin": null,
      "release": "sid",
      "urgency": "not yet assigned",
      "fixed_version": "1:1.8.7-r2-1"
    },
    {
      "bug": 1136211,
      "name": "libsixel",
      "type": "source",
      "origin": null,
      "release": "forky",
      "urgency": "not yet assigned",
      "fixed_version": "1:1.8.7-r2-1"
    },
    {
      "bug": 1136211,
      "name": "libsixel",
      "type": "source",
      "origin": null,
      "release": "trixie",
      "urgency": "not yet assigned",
      "fixed_version": ""
    },
    {
      "bug": 1136211,
      "name": "libsixel",
      "type": "source",
      "origin": null,
      "release": "bookworm",
      "urgency": "not yet assigned",
      "fixed_version": ""
    }
  ],
  "distribution_packages": [
    {
      "name": "libsixel",
      "ecosystem": "cpe",
      "fixed_version": "not yet fixed"
    },
    {
      "name": "libsixel",
      "ecosystem": "cpe",
      "fixed_version": "1.8.7-r1"
    }
  ]
}

[Debian bug #1136211]

Publisher notes

[trixie] libsixel: Minor issue [bookworm] libsixel: Minor issue

OpenFactory catalog packages

Matching against OpenFactory catalog package versions is in progress.

[Debian 12 (Bookworm)]

  • [libsixel1]Unknown

    Source package: [libsixel]

    Details (2)

    • 1.10.3-3 · amd64 · bookworm

      Affected

      nvd · libsixel · debian · bookworm; nvd · libsixel · debian · 12

    • 1.10.3-3 · arm64 · bookworm

      Affected

      nvd · libsixel · debian · bookworm; nvd · libsixel · debian · 12

  • [libsixel-bin]Unknown

    Source package: [libsixel]

    Details (2)

    • 1.10.3-3 · amd64 · bookworm

      Affected

      nvd · libsixel · debian · bookworm; nvd · libsixel · debian · 12

    • 1.10.3-3 · arm64 · bookworm

      Affected

      nvd · libsixel · debian · bookworm; nvd · libsixel · debian · 12

  • [libsixel-dev]Unknown

    Source package: [libsixel]

    Details (2)

    • 1.10.3-3 · amd64 · bookworm

      Affected

      nvd · libsixel · debian · bookworm; nvd · libsixel · debian · 12

    • 1.10.3-3 · arm64 · bookworm

      Affected

      nvd · libsixel · debian · bookworm; nvd · libsixel · debian · 12

  • [libsixel-examples]Unknown

    Source package: [libsixel]

    Details (2)

    • 1.10.3-3 · all · bookworm

      Affected

      nvd · libsixel · debian · bookworm; nvd · libsixel · debian · 12

    • 1.10.3-3 · all · bookworm

      Affected

      nvd · libsixel · debian · bookworm; nvd · libsixel · debian · 12

[Debian 13 (Trixie)]

  • [libsixel1]Unknown

    Source package: [libsixel]

    Details (2)

    • 1.10.5-1 · amd64 · trixie

      Affected

      nvd · libsixel · debian · 13

    • 1.10.5-1 · arm64 · trixie

      Affected

      nvd · libsixel · debian · 13

  • [libsixel-bin]Unknown

    Source package: [libsixel]

    Details (2)

    • 1.10.5-1 · amd64 · trixie

      Affected

      nvd · libsixel · debian · 13

    • 1.10.5-1 · arm64 · trixie

      Affected

      nvd · libsixel · debian · 13

  • [libsixel-dev]Unknown

    Source package: [libsixel]

    Details (2)

    • 1.10.5-1 · amd64 · trixie

      Affected

      nvd · libsixel · debian · 13

    • 1.10.5-1 · arm64 · trixie

      Affected

      nvd · libsixel · debian · 13

  • [libsixel-examples]Unknown

    Source package: [libsixel]

    Details (2)

    • 1.10.5-1 · all · trixie

      Affected

      nvd · libsixel · debian · 13

    • 1.10.5-1 · all · trixie

      Affected

      nvd · libsixel · debian · 13

Observed:

References

[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]