Red Hat Enterprise Linux 7 Extended Lifecycle…: Off-by-one Error
CVE-2026-4887 is a high-severity off-by-one error vulnerability in Red Hat Enterprise Linux 7 Extended Lifecycle Support from Red Hat, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. There is no confirmed exploitation so far. EPSS estimates a 0.66% chance of exploitation within 30 days, higher than 52% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Gimp to 3.2.0 or a later version.
- Read the advisory on access.redhat.com for workarounds and exact fixed builds.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 6.1 | Medium | CNA (redhat.com) |
| CVSS 3.1 | 7.1 | High | NVD |
Official description
A flaw was found in GIMP. This issue is a heap buffer over-read in GIMP PCX file loader due to an off-by-one error. A remote attacker could exploit this by convincing a user to open a specially crafted PCX image. Successful exploitation could lead to out-of-bounds memory disclosure and a possible application crash, resulting in a Denial of Service (DoS).
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Off-by-one Error
A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value.
How developers prevent this class of flaw
- When copying character arrays or using character manipulation methods, the correct size parameter must be used to account for the null terminator that needs to be added at the end of the array. Some examples of functions susceptible to this weakness in C include strcpy(), strncpy(), strcat(), strncat(), printf(), sprintf(), scanf() and sscanf().
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- access.redhat.com/security/cve/CVE-2026-4887Mitigation
- bugzilla.redhat.com/show_bug.cgi?id=2451669Issue Tracking
Technical write-ups (may include proof of concept)
- gitlab.gnome.org/GNOME/gimp/-/issues/15960Exploit, Issue Tracking
Other references
- access.redhat.com/errata/RHSA-2026:16484
- access.redhat.com/errata/RHSA-2026:17533
- access.redhat.com/errata/RHSA-2026:19362
- access.redhat.com/errata/RHSA-2026:20552
- access.redhat.com/errata/RHSA-2026:20553
- access.redhat.com/errata/RHSA-2026:20554
- access.redhat.com/errata/RHSA-2026:20691
- access.redhat.com/errata/RHSA-2026:25899
- access.redhat.com/errata/RHSA-2026:25901
- access.redhat.com/errata/RHSA-2026:25907
- access.redhat.com/errata/RHSA-2026:26168
Other vulnerabilities in Red Hat Enterprise Linux 7 Extended Lifecycle Support
- 8.6 High severity
- 8.6 High severity
- 8.6 High severity
- 8.6 High severity
- 7.5 High severity
- 7.8 High severity
Recent Off-by-one Error vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 8.4 High severity
- 7.5 High severity
- 9.8 Critical severity
- 10.0 Critical severity
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