CVE-2026-55244: lmfit asteval · Uncaught Exception
Affects lmfit astevalSource CVE Database V5
Not known to be exploited · CVSS 5.0 Medium : upgrade to 1.0.9 when convenient.
Data as of 29 Oct 2026, 19:04 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.0.9
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 14 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade lmfit asteval to 1.0.9.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| lmfitasteval | Affected
| Fixed in
|
PyPIastevalpkg:pypi/astevalOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade to asteval version 1.0.9 or later, where this issue is fixed. No other mitigation is indicated by the vendor advisory.
Description
A vulnerability in the asteval Python expression evaluator prior to version 1.0.9 allows certain BaseException subclasses (BaseException, SystemExit, KeyboardInterrupt, GeneratorExit) raised by attacker-controlled expressions to bypass the interpreter's safety handlers. This can cause the consuming application to terminate unexpectedly or disrupt signal and cleanup handling, resulting in denial of service. The issue is fixed in version 1.0.9.
References
- github.com/lmfit/asteval/security/advisories/GHSA-89v8-rhwq-hf77 (opens in a new tab)
- github.com/lmfit/asteval/pull/153 (opens in a new tab)
- github.com/lmfit/asteval/commit/9c625b3674f8d05f206708bb85afca17a87694a4 (opens in a new tab)
- github.com/lmfit/asteval/commit/c49c99a67acb63eb7410231932250bd820380e45 (opens in a new tab)
- github.com/lmfit/asteval/releases/tag/1.0.9 (opens in a new tab)