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Fencer Intel
medium 4.2

CVE-2025-26603 json

heap-use-after-free in function str_to_reg in vim/vim

published last yr. modified 4mo ago also EUVD-2025-5099

cvss
4.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits
0
none known

Summary

Vim is a greatly improved version of the good old UNIX editor Vi. Vim allows to redirect screen messages using the `:redir` ex command to register, variables and files. It also allows to show the contents of registers using the `:registers` or `:display` ex command. When redirecting the output of `:display` to a register, Vim will free the register content before storing the new content in the register. Now when redirecting the `:display` command to a register that is being displayed, Vim will free the content while shortly afterwards trying to access it, which leads to a use-after-free. Vim pre 9.1.1115 checks in the ex_display() function, that it does not try to redirect to a register while displaying this register at the same time. However this check is not complete, and so Vim does not check the `+` and `*` registers (which typically donate the X11/clipboard registers, and when a clipboard connection is not possible will fall back to use register 0 instead. In Patch 9.1.1115 Vim will therefore skip outputting to register zero when trying to redirect to the clipboard registers `*` or `+`. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Patch / fix

  • vim vim 9.1.1115
  • vim Debian 14, Debian 13 2:9.1.1230-1

debian advisories DEBIAN-CVE-2025-26603

  • vim Ubuntu 20.04 LTS 2:8.1.2269-1ubuntu5.32
  • vim Ubuntu 22.04 LTS 2:8.2.3995-1ubuntu2.24
  • vim Ubuntu 24.04 LTS 2:9.1.0016-1ubuntu7.8
  • vim Ubuntu Pro 14.04 LTS 2:7.4.052-1ubuntu3.1+esm21
  • vim Ubuntu Pro 16.04 LTS 2:7.4.1689-3ubuntu1.5+esm27
  • vim Ubuntu Pro 18.04 LTS 2:8.0.1453-1ubuntu1.13+esm12

ubuntu advisories UBUNTU-CVE-2025-26603

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • vim Alpine 3.24, Alpine 3.23, Alpine 3.22 9.1.1164-r0

alpine advisories ALPINE-CVE-2025-26603

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • vim CBL-Mariner 2.0, Azure Linux 3.0 9.1.0791-4

azure linux advisories AZL-56913AZL-56962

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-26603 updated cvss 4.2

vim: heap-use-after-free in function str_to_reg in vim/vim

  • Red Hat Enterprise Linux 6 vim, vim-X11, vim-common, vim-minimal, vim-enhanced, vim-filesystem Red Hat Enterprise Linux 7 vim, vim-X11, vim-common, vim-minimal, vim-enhanced, vim-filesystem Red Hat Enterprise Linux 8 vim, vim-X11, vim-common, vim-minimal, vim-enhanced, vim-filesystem
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 9 vim, vim-X11, vim-common, vim-minimal, vim-enhanced, vim-filesystem Red Hat Enterprise Linux 10 vim Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-9
    affected: workaround, no fix available “Fix deferred”
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-dashboard-rhel9
    under investigation

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
last yr.

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 4.2 CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:L

Affected products

  • vim vim

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.