SB2026052537 - Multiple vulnerabilities in Vim

Description

This security bulletin contains information about 3 vulnerabilities.

1) Use of uninitialized resource (CVE-ID: N/A)

CWE-ID: CWE-908 - Use of Uninitialized Resource

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to cause a denial of service and disclose sensitive information.

The vulnerability exists due to use of uninitialized resource in read_tree_node() and the Vim spell file parser when parsing a crafted spell file. A remote attacker can supply a crafted .spl file with a BY_INDEX shared-node reference to trigger out-of-bounds heap reads to cause a denial of service and disclose sensitive information.

Exploitation requires a malicious .spl file to be present on the runtimepath and the victim to enable spell checking with the matching language or open a text file whose modeline sets 'spelllang' and enables 'spell' while 'modeline' is enabled.

2) Out-of-bounds read (CVE-ID: N/A)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to out-of-bounds read in tree_count_words() when parsing a crafted spell file. A remote attacker can supply a crafted .spl file to trigger a one-byte heap out-of-bounds read to cause a denial of service.

The issue is triggered during .sug file loading on a tree whose final sibling is BY_NOFLAGS.

3) Uncontrolled Recursion (CVE-ID: N/A)

CWE-ID: CWE-674 - Uncontrolled Recursion

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to uncontrolled recursion in read_tree_node() when parsing a crafted spell file. A remote attacker can supply a crafted .spl file containing a deep linear node chain to cause a denial of service.

On default 8 MB stacks, approximately 88,000 nested frames can exhaust the stack and crash Vim with SIGSEGV.

Remediation

Install update from vendor's website.

References

• https://github.com/vim/vim/security/advisories/GHSA-3h95-3962-mmvf
• https://github.com/vim/vim/commit/25e4e46c584840806b45da20ed