CVE-2026-63209

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.50% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 42.6% of scored records. A rank, not a probability.

NVD base score

7.5 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

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

NVD analysis status

Deferred. NVD last modified this record on 2026-09-30.

Red Hat severity

Important. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-09-29 14:58Z1 MO AGO

Last updated

2026-09-29 16:32Z1 MO AGO

Reserved

2026-07-15

Assigning CNA

GitHub_M

Record state

PUBLISHED

Severity

High (CVSS 7.5)

CNA CVSS vector

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

Weaknesses

• CWE-190Integer Overflow or WraparoundBase
• CWE-787Out-of-bounds WriteBase
• CWE-823Use of Out-of-range Pointer OffsetBase

Data version

5.2

Document digest

597132869ebb870f20b50cc97d6078da131dbeccd6de0ebc805025def877b554

• github.comhttps://github.com/klauspost/compress/security/advisories/GHSA-259r-337f-4rfwx_refsource_CONFIRM
• github.comhttps://github.com/klauspost/compress/commit/539243b8823ee8f03e49969823d57c348c917536x_refsource_MISC
• github.comhttps://github.com/klauspost/compress/releases/tag/v1.18.7x_refsource_MISC