Security readout for executives and security teams
Plain-English summary
fmtlib before 4.1.0 could crash when fmt::print() receives an invalid format specifier. In affected applications, this can become a denial-of-service issue if an attacker can influence the format string. The public record does not show active exploitation or a broader compromise impact.
Executive priority
Treat as a targeted availability risk, not confirmed widespread exploitation. Prioritize remediation where fmtlib is exposed through user-facing or internet-facing request processing, and handle other internal-only uses through normal dependency maintenance.
Technical view
CVE-2018-1000052 is a fmtlib memory corruption issue described as SIGSEGV and invalid write in fmt::print(), associated with CWE-134. Sources state versions before 4.1.0, before the referenced fix lineage, are affected and that the issue was fixed after commit 8cf30aa2be256eba07bb1cefb998c52326e846e7.
Likely exposure
Exposure is most likely in C++ applications bundling or linking fmtlib before 4.1.0, especially where externally influenced data can reach fmt::print() format handling. The CVE record does not name downstream products or package distributions.
Exploitation context
The source bundle says exploitation appears possible by specifying an invalid format specifier, resulting in SIGSEGV and denial of service. There is no KEV listing and no cited evidence of active exploitation.
Researcher notes
Public evidence is limited to the CVE entry, upstream issue, and fix commit. No CVSS score, downstream affected product list, or KEV exploitation evidence is provided in the bundle, so exposure must be validated locally.
Mitigation direction
- Upgrade fmtlib to version 4.1.0 or later.
- Use a vendor-supported build containing the referenced fix commit.
- Check vendor advisories for packaged or transitive fmtlib copies.
- Avoid externally controlled format strings in fmt::print() call paths.
Validation and detection
- Inventory direct and vendored fmtlib versions in affected codebases.
- Confirm builds use fmtlib 4.1.0 or a fixed commit.
- Review fmt::print() call sites for externally influenced format strings.
- Check crash reports for unexplained SIGSEGV in fmt formatting paths.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CVE-2018-1000052 mapping review
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Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/fmtlib/fmt/commit/8cf30aa2be256eba07bb1cefb998c52326e846e7CVE reference · x_refsource_CONFIRM
- https://github.com/fmtlib/fmt/issues/642CVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.